Robert hated his hometown

[Bassim]

Have I made any mistakes?

Robert hated his hometown because of all the intrigues, gossip and small quarrels over trifles, which seemed to be the main interests of its citizens. He could barely wait to leave it and vowed never to return. He often felt as if he lived in a large prison camp where every moment was regulated and you were expected to behave according to the rules or face consequences. Robert hated uniformity and would rather live in a squalor and poverty than obey some authority who dictated what was the best for you. He even pitied his own parents who lived well and could buy almost anything they wanted but would never dream of rebelling.

 

[abaka]

Your grammar is very good. The minimum required changes are one article and several commas:

He often felt as if he lived in a large prison camp where every moment was regulated, and you were expected to behave according to the rules or face consequences. ...would rather live in squalor and ... He even pitied his own parents, who lived well and could buy almost anything they wanted, but would never dream of rebelling.

The following are purely stylistic suggestions made for a native-level speaker of English. Take them or leave them, as you will.

Robert hated his hometown. Intrigues, gossip and small quarrels over trifles seemed to be the main interests of its citizens.

Robert's hatred for his hometown is the topic of your paragraph. It deserves its own sentence: everything else is examples and consequences of his hatred. Implicitly obvious reasons need no explicit causative, so I suggest striking out the "because".

He could barely wait to leave it, and when he did, vowed never to return.

There's a strong inference that in fact he has left, but the sequence of his thoughts is not quite clear until you mention his leaving. If he has not left, I think you really must add that, at the very end of the paragraph.

He had often felt as if he lived in a large prison camp where every moment was regulated, and you were expected to follow the rules or face consequences.

Why "had"? He's already left. (Unless he has not...) "Follow the rules" is the idiom.

Robert hated uniformity and would rather live in squalor and poverty than obey the dictates of some authority that dictated what was the best for you.

The "that" makes the authority less personal and therefore more threatening. A person with authority (who dictates) is a positive figure, one you follow willingly.

He even pitied his own parents, who lived well and could buy almost anything they wanted, but would never dream of rebelling.

 

[Bassim]

abaka,

Thank you so much for your detailed explanations and suggestions.

I used "had" because I imagined Robert still lived in his hometown.

 

[abaka]

Oh, I see. That's really critical. Omit the "had", then. And for your last sentence, mention that Robert still lived there, to add the ironic twist at the end.

Or, if you prefer, change the sentence about hardly waiting to leave. Perhaps:

He could barely wait to leave it and promised himself he would never return.

A vow is something you take when you act: a marriage vow, for example. Before the deed has been done, it's merely a promise.