Can Buddhism be interpreted as a quest for the young?

Even young people nowdays remain engaged in murder, rape, etc.
Calm down
Dhamma is not specific to age. Many old citizens acheived arhant stage during buddha's time, although they were guided by &under the powerful compassion of supreme teacher himself.
Learning dhamma has nothing to do with age. Although, old geezers tend to stuck in preception gained&maintained since young age, it doesn't mean that they can't learn dhamma and rectify their bad views.

Would like to suggest you to go for dedicated meditation(on daily basis) and see for yourself "Ehi Passiko".

I’m the kind of person who cannot obey as wanted blindly, there must always be a reason when it comes to rules rather than spirit.
rather than spirit:: why do you wish to blindly follow an unseen, unfelt thing? Why do you follow something whose body&mind effect remains undetermined? Even when it comes from those speakers who are not established in dhamma.
What would it benefit you to know those(spirits in your case), knowing whom your defiled behaviour remain same, knowing whom your tendency to reasoning doesn't stop, knowing whom all your misunderstandings haven't finished till now?

Story
There was once a man, a drunken man-- addicted to drinking, addicted to spending all his money on drinking alcohal. Nothing worked to stop him, god didn't help, angels fled away, tantriks bowed to him, meditators got tired of yelling at him,...
Then, a time comes when his health suddenly got deteriorated, he remained at hospital for 1 full month.
Later, doctor said, "If you don't quit drinking your daughter and wife will be on road, either for begging or for ***".
He never even thought about drinks again.

Last words:: Buddha's teachings are meant to remove bad-habbits, for one must first accept them faithfully, practice them faithfully, then test, judge and compare them with other philosophies. If find useful, follow them.
Still
It doesn't mean that, "accept them blindly" or "practice them blindly" or "test, judge and compare them blindly".
Faith must be on Buddha as a set of those qualities that guide us to dhamma, that guide us to liberation.

When we take refuge in buddha, we take refuge in these qualities not in god or angel or some unknown atta.

It's all about faith and dedication in righteousness, not about age-clumsiness.

Metta.

Can Buddhism be interpreted as a quest for the young?

I see it as guidelines for staying out of trouble, maybe helping out.

I used to think that the beauty of Buddhism laid within the absence of rules and restrictions.

What do or did you think that Buddhism is? What belief, what practice, what doctrine, what school/tradition? That's not evident.

That you won’t be condemned for foing what you think is right.

I think Buddhist doctrine is that each being inherits their own kamma.

For example, if you marry then you become "married" -- not "condemned".

That there is more to see than just “here” and now.

I used to think that too about Buddhism, and I didn't understand it.

But seeing it as a quest also makes me sad that if it doesn’t make sense to my senses and comprehension anymore.

I mentioned previously it might be the opposite of a quest -- perhaps it's how to stop questing.

Doubly so if "questing" implies a quest for something fictional (or impermanent, unsatisfactory).

I don't know but you give me the impression of being quite confused. Are you feeding your mind on an exclusive diet of pop songs at the moment?

I find it helps to consider -- "what is virtuous? what is good behaviour?"

And helpful to meet different people -- who are mostly-all adults now but otherwise of all ages, including older and younger.

I’m the kind of person who cannot obey as wanted blindly, there must always be a reason when it comes to rules rather than spirit.

I don't remember what tradition this is from (not Buddhist) but I read once that (I paraphrase), "Man is inclined to worship anything -- God; a woman; a child; gold; ...".

Buddhist doctrine maybe starts with something along the lines of, "Don't tell lies, be kind to people."

Or "All tremble at violence; all fear death. Putting oneself in the place of another, one should not kill nor cause another to kill."

I see this as axiomatic (and agreeable). And doctrine like the Kalama sutta imply that Buddhism is meant to be (or, at a minimum, to include) good common sense.

I don’t really stay if this is what is required of me. I don’t need rules, I need companionship, wherever they are or are not.

That's perhaps a psychological need which Buddhism recognises.

Upaddha Sutta: Half (SN 45.2)

As he was sitting there, Ven. Ananda said to the Blessed One, "This is half of the holy life, lord: admirable friendship, admirable companionship, admirable camaraderie."[1]

"Don't say that, Ananda. Don't say that. Admirable friendship, admirable companionship, admirable camaraderie is actually the whole of the holy life. When a monk has admirable people as friends, companions, & comrades, he can be expected to develop & pursue the noble eightfold path.

Footnote:

As AN 8.54 points out, this means not only associating with good people, but also learning from them and emulating their good qualities.

But I’m 35 this year and already I fear the setting sun.

We're warned that "self-views" are an occasion for suffering to arise.

I wish I could explain that, it (together with the noble truths) is one of the more helpful bits of Buddhist doctrine, and apparently difficult to really understand. There are a lot of questions and answers more-or-less related to that on this site.

I know that I too will need a house of my own, made of rules and rituals and security.

Again, I don't know what you think Buddhism is.

According to the suttas, the first three fetters abandoned on the way to liberation are:

1. belief in a self (Pali: sakkāya-diṭṭhi)[7]
2. doubt or uncertainty (vicikicchā)[8]
3. attachment to rites and rituals (sīlabbata-parāmāsa)[9]

See also "house-builder".

How can I say anything against that, though I can’t muzzle my dread?

Read or listen to the doctrine? Talk with a teacher or a good friend?

I am beginning to understand why older people don’t change much, though I wish I can be their gentle mare.

Um, yeah, I'm not sure that's a good generalisation either.

About a gentle mare if that's your wish, another thing I read once (though again not Buddhist), "To have a friend, you have to be one." There are a lot of older people about.

One can speak of many rules but there are rules which are hard to break such as old age, disease and death. Those are the real rules and restrictions that most people obey blindly.