Was the Buddha against violence in all situations?

There's a book titled, In Defense of Dharma: Just-war Ideology in Buddhist Sri Lanka.

This review of it (by Annewieke Vroom in the Journal of Buddhist Ethics) includes,

Nationalist stories

In chapter two, "Just-war Thinking in Texts and Contexts," Bartholomeusz describes what narratives are used to justify Buddhist violence. The major culprit here is the post-canonical scripture the Mahavamsa (Great History). In this text kings and forefathers defend the country from "external influences" after the Buddha himself makes three magical trips to Sri Lanka, which he prepares to be the dharmadwipa (island of the dharma). "[T]he Mahavamsa occupies the same position in Sinhala society that the Ramayana holds in Indian society." Bartholomeusz quotes Steven Kemper on the importance of this text: "As children, they hear shreds and patches of the tradition recited, they see temple paintings evoking it, or they follow cartoons in Sinhala newspapers representing the lives of righteous kings." (pp. 20-21) Thus Bartholomeusz portrays the background of the Sri Lankan Buddhist perception of the island: stories that present the island as destined to be Buddhist.

Really Buddhist

Sri Lankan Buddhist religio-nationalism is supported by the monks who are understood to have the task to safeguard the "Dharma-Island" from threat by "foreign influences" such as the Tamils. In support of this nationalist worldview, many texts are quoted that paint the history of the island as one of heroic warrior kings who (violently) "defend" the country from damilas (now read as Tamils) (chapter three: "Dharma yuddhaya and Dharma Warriors in Sri Lanka"). Even though most of the quoted texts are post-canonical, Bartholomeusz stresses as in earlier publications that it is naive to explain dharma yuddhaya (religious/dharma-war) thinking as a post-Theravāda development, a Sri Lankan aberration, or for other reasons not "truly Buddhist." (p. 66) She locates the seeds for violence in canonical Buddhist texts such as the Dhammapada, that are "replete with military metaphors." (p. 41)

In summary, "The major culprit here is the post-canonical scripture the Mahavamsa (Great History)."

I don't have the book, so I can't tell you what it's citing from canonical literature. One of the "military metaphors in the Dhammapada" might be the first verse of Chapter 23 (though in my opinion using that to justify war would be taking it out of context).

Verse 320: As an elephant in battlefield withstands the arrow shot from a bow, so shall I endure abuse. Indeed, many people are without morality.

See also, What does Buddha and Buddhism say about fighting against enemy of dharma?

You might be more interested in Thailand. There's a book Buddhist Fury: Religion and Violence in Southern Thailand, which is reviewed here, and which is quoted on Wikipedia as saying that,

In the 1970s, nationalist Buddhist monks like Phra Kittiwuttho argued that killing Communists did not violate any of the Buddhist precepts. The militant side of Thai Buddhism became prominent again in 2004 when a Malay Muslim insurgency renewed in Thailand's deep south. Since January 2004, the Thai government has converted Buddhist monasteries into military outposts, commissioned Buddhist military monks and given support to Buddhist vigilante squads.

The review (I haven't read the book) suggests that the justification or reasoning for this is identification with nationalism (e.g. "Thailand is Buddhist").

Your occupation doesn't determine.

But there are occupations that could fall you victim of bad karma.

You can compensate it through practicimg Dharma and helping others.

No matter what , violence is against Dhamma. Killing is Killing. Harming is Harming.

It's hard to prove a negative but in this article, Getting the Message, Thanissaro Bhikkhu emphasizes "no killing":

When asked if there was anything whose killing he approved of, the Buddha answered that there was only one thing: anger. In no recorded instance did he approve of killing any living being at all. When one of his monks went to an executioner and told the man to kill his victims compassionately, with one blow, rather than torturing them, the Buddha expelled the monk from the Sangha, on the grounds that even the recommendation to kill compassionately is still a recommendation to kill — something he would never condone. If a monk was physically attacked, the Buddha allowed him to strike back in self-defense, but never with the intention to kill.

This might answer your question about "violence", too: apparently "striking back in self-defense" might be OK (I guess that might be in the Vinaya rather than a sutta), but not killing.

I think the Vinaya also recommends avoiding violence, by the way (e.g. avoid going to a place where there are known to be robbers).

actually everything is in the suttas and for the purpose of the answer Buddhism i equate with Buddhadhamma, not sure what meaning the inquirer imparts it

And how, householders, are there three kinds of bodily conduct not in accordance with the Dhamma, unrighteous conduct? Here someone kills living beings; he is murderous, bloody-handed, given to blows and violence, merciless to living beings.

So, householders, it is by reason of such conduct not in accordance with the Dhamma, by reason of such unrighteous conduct that some beings here on the dissolution of the body, after death, reappear in states of deprivation, in an unhappy destination, in perdition, even in hell.

Saleyyaka sutta (MN 41)

one could be a Buddhist who got caught up in unfortunate circumstances where they are forced to use violence or a deadly force which they wouldn't use otherwise, but they'll still have to experience kammic consequences, which is normally birth in hell

such a kamma i think to a certain degree can be alleviated if the mind isn't clouded and blinded with defilements, first of all with desire of killing, at the time of its (the kamma) creation

Again, with sensual pleasures as the cause, sensual pleasures as the source, sensual pleasures as the basis, the cause being simply sensual pleasures, men take swords and shields and buckle on bows and quivers, and they charge into battle massed in double array with arrows and spears flying and swords flashing; and there they are wounded by arrows and spears, and their heads are cut off by swords, whereby they incur death or deadly suffering.

Now this is a danger in the case of sensual pleasures, a mass of suffering visible here and now, having sensual pleasures as its cause, sensual pleasures as its source, sensual pleasures as its basis, the cause being simply sensual pleasures.

Again, with sensual pleasures as the cause, sensual pleasures as the source, sensual pleasures as the basis, the cause being simply sensual pleasures, men take swords and shields and buckle on bows and quivers, and they charge slippery bastions, with arrows and spears flying and swords flashing; and there they are wounded by arrows and spears and splashed with boiling liquids and crushed under heavy weights, and their heads are cut off by swords, whereby they incur death or deadly suffering.

Now this is a danger in the case of sensual pleasures, a mass of suffering visible here and now, having sensual pleasures as its cause, sensual pleasures as its source, sensual pleasures as its basis, the cause being simply sensual pleasures.

Mahadukkhakkhandha sutta (MN 13)

When a warrior strives & exerts himself in battle, his mind is already seized, debased, & misdirected by the thought: 'May these beings be struck down or slaughtered or annihilated or destroyed. May they not exist.' If others then strike him down & slay him while he is thus striving & exerting himself in battle, then with the breakup of the body, after death, he is reborn in the hell called the realm of those slain in battle. But if he holds such a view as this: 'When a warrior strives & exerts himself in battle, if others then strike him down & slay him while he is striving & exerting himself in battle, then with the breakup of the body, after death, he is reborn in the company of devas slain in battle,' that is his wrong view. Now, there are two destinations for a person with wrong view, I tell you: either hell or the animal womb."

Yodhajiva sutta (SN 42.3)

one who is a Buddhist serving in a military during peace time with intent to slack on his duty at the high noon in favor of his obligations as a Buddhist, i think would be committing verbal misconduct of lying

Here's how Ajahn Sucitto of Cittaviveka Vihara describes his encounter with road bandits while on a pilgrimage in India

Then everything blew up. Nick turned round with a menacing expression on his face; someone was tugging my robe on one side while the first man was hauling frantically at the mug on its strap on the other.
Three men charged at Nick who was crouched boxer-style; he wheeled and hit them with his backpack, then ran off with the three of them in hot pursuit. I was being lugged in two directions simultaneously by the strap on my water bottle and on my bag, I could only try to get the stuff off and let them have it, but their pulling on it made that impossible. We were going round in circles, with their excitement spinning into frenzy . I had to stop this. “Wait! Wait! Let me get this stuff off !” Momentarily they stood still. They all had axes and staves. The leader glared at me through twisted features and raised his axe.
Funny how your mind goes clear when the options disappear. Why struggle against the inevitable? The only freedom was to go without fear. I bowed my head and pointed the top of my skull toward him, drew the blade of my hand along it from the crown of my head to the brow. “Hit it right there.” Something shifted; he backed off, waving his axe and muttering angrily. I stepped forward and repeated the action. Give it away; let it all go.
Things settled. He lowered his axe. I slipped off the bag and the water bottle and stepped back. The three of them began excitedly picking over the treasure. I imagined that they’d rummage around, find there was nothing there of any value, and run off. Two of them picked up the gear and scurried down the track away. I felt shaky and sat down. Better keep cool — I started chanting softly. Then Nick ambled along with a smile but without his pack or assailants. “I’ve hidden the money; Bhante, are you all right?”
His return signalled further frenzy. As his assailants returned, the men charged at him with their sticks and began swinging blows; Nick caught most of them on his arms: “ All right, all right! I’ll show you where.” And the mob had streamed off into the forest by the time that I got to my feet, leaving me with one lad, who sullenly resisted my attempts to strike up a conversation. But he was mellow compared to the older men when they returned — without Nick or the bags. They jumped on me and pulled off the bag that I had around my neck containing the relics and Buddha image; they ripped off the waistband that was threaded through my pouch; they clawed under my sabong and dragged the passport out of another pouch that was hanging around my waist.
Then they were off with the loot tied up in bundles on their heads. The leader turned round and said “Your bags are over there,” pointing into the forest. “Fine, OK.” I said, in a vaguely warm way . The forest went back to silence as usual ... a sunny day, with the forested slopes on either side.

"Rude Awakenings" (pp. 238-239) https://www.youtube.com/watch?v=r9YE1oP-qr0#t=1h1m15s