Yes and Yes.

Those ideas were confirmed in a Q&A, I don't remember which one, though

Yes, the more a particular path is traveled upon, the more worn it becomes. Also, new roads may be built of differing quality, as well as improving existing roads and paths.

Can't find the corresponding Q&A or DJ.

Well, I've only listened to 3 hours of Q&A, so long ways to go...thanks guys.