Mild and severe forms of the three poisons

(A Mahayana explanation:)

Lobha

-- The opposite of lobha is apparently generosity. Is this right?

In my opinion, this is not accurate. The opposite of lobha is dispassion, equanimity - the feeling that you can be happy with whatever you have. In my understanding, lobha is not as much miserliness or tendency to keep things to oneself -- as it is a feeling of lacking something, having some sort of emotional hole -- that one then tries to fill with all sorts of objects, projects, and experiences. This emotional hole then manifests as all kinds of impulsive desires and obsessions.

Generosity is an antidote to lobha, not it's "opposite". The way it works IMO, is when you give something to others, your emotional mind starts feeling that since you're giving - you therefore must be having an abundance of something that others don't have - and that feeling of abundance leads to (partial) healing of the emotional hole of neediness. This is an example of idappaccayata at work.

--...to make a good impression on others? -- correct, craving for praise is a manifestation of lobha.

-- enjoyment of nice pleasant weather or tasty food, and the desire that it should continue further? -- I don't think this is an example of lobha. At the moment of enjoyment you don't normally have what we call "desire". You may have lingering fear of it eventually running out - that's a manifestation of dosa. Once it stops, you may have nostalgia and craving for it to come back - that's a manifestation of lobha.

--looking at a good-looking person and desiring to go and talk to them? -- correct, this is a manifestation of lobha, you feeling a need for a positive experience.

--What about feeling happy when being praised by others? -- feeling happy in and of itself is not lobha. It's when we crave for an external source of satisfaction, since we lost touch with our own. Seeking praise yes, that's from lobha.

Dosa

--The opposite of dosa is apparently loving-kindness (metta or maitri). Is this right?

Again, metta is an antidote to dosa, not it's opposite. The opposite of dosa is equanimity or wise acceptance.

--anger that results in the act of killing or injuring others - IMO anger is a manifestation of dosa, not an example of it. Dosa is an emotional negativity, or emotional irritability, a deep lying attitude that "this is all wrong". (I suppose it comes from some sort of unconscious attachment to an impossible ideal of external perfection. If lobha is about being deeply unhappy with oneself because of not having been loved enough, dosa is about being deeply unhappy with the world, because of having lost the object of one's love.)

-- the dislike of unpleasant weather (too hot and humid, or too cold) -- if you feel that bad weather is "wrong", like it's a corruption of good weather - that's from dosa; if you feel that you're missing the positive emotions that come from good weather - that's from lobha.

-- the dislike of minor physical pain and wishing that it goes away? -- correct, any feeling that something "should not be" because it's "not right" or "not supposed to be this way" - is from dosa.

-- judging others in your mind for their perceived flaws? -- definitely comes from dosa.

-- being impatient because your friend is late to meet you for dinner? -- if in your mind you are mostly craving to have that dinner faster - that comes from lobha, if you are angry at your friend for being late - that comes from dosa.

-- feeling displeased because you were criticized by others? -- in my opinion this is from lobha. Being criticized is a type of rejection, and being vulnerable to rejection comes from lobha. Now, if you are also angry at them, because you think they are wrong - that part is from 'dosa'.

Moha

-- The opposite of delusion (moha) is apparently wisdom (panna or prajna). Is this right? -- I think this is right. The opposite of delusion is "correct understanding".

--Could depression, anxiety, rage, terror, remorse be considered severe forms of delusion? - no, here you are confusing the root of the emotion and the manifestation of the emotion.

...Or is this often linked to the [other two], and seldom exists standalone?

The traditional explanation is that emotions are like colors, Three Poisons being the three basic colors that can be mixed to create the rest. I don't like this explanation, because it creates impression that Three Poisons are some sort of main prototypical emotions. They are not, they are roots that emotions come from.

Moha is a collection of formulas in your mind that incorrectly describes how things work. It came from observation of real experiences but incorrect understanding of the mechanisms behind these experiences.

-- For example, I judge someone negatively in my mind, but it's actually because I did not understand the reason why they are in that situation? --correct, now you got it. This example is a combination of moha leading to incorrect understanding and dosa leading to qualitative judgement.

-- Or I do things like dressing up better for getting recognition from others... -- I think this one is mostly lobha or deep-lying craving for positive experiences. It would be moha if you dressed-up going to a zoo.

-- ...but it's actually because I have the wrong notion of putting too much importance into that recognition? - the fundamental delusion that considers worldly sources of happiness, worldly injustices, and the world itself as something that exists objectively, independently of one's interpretation - and therefore takes them as all-important, is usually called avidya, not moha. Avidya is the deepest and subtlest factor that always underlies all three of lobha, dosa, and moha.

Other types of negative mental states

-- How do other types of negative mental states like envy, sloth, conceit, miserliness, restlessness, lack of shame etc. (list of other unwholesome mental states here) connect to the three unwholesome roots?

It is said that they all come from a combination of the three roots and the underlying avidya.

Avidya confuses reality with interpretation. It therefore incorrectly attributes pleasant&unpleasant/right&wrong characteristics to external objects, while in reality they come from ourselves. Then Lobha comes from assumption that one's feeling of lacking something can be cured by pursuing external goals. And Dosa comes from assumption that some things are truly "good" and "right" and some things are "bad" and "wrong" forgetting that this is only our interpretation. Moha comes from assuming our superficial observations as real and coming to incorrect conclusions based on them.

From combination of pursuing external sources of happiness (lobha), judging things as inherently [good or] bad (dosa), and being certain that our partial observations are reality (moha) - comes mismatch between "is" and "should". This mismatch feels as suffering. Then from the three roots plus suffering comes confused action. This confused action creates causes for future confusion.

When we correctly understand that reality is our interpretation... That the source of happiness and unhappiness is our own mind... Then we no longer pursue external sources of happiness... We don't judge things as inherrently [good or] bad, we do not confuse our experiences with reality... Then we can stop maintaining the vicious circle of confused action... We can start reducing the conflict between "is" and "should"... The complete removal of this conflict, from coarse to very subtle, feels as complete harmony, also known as Nirvana.