If you are in the Honors College the honors classes are usually 15 people. You won’t be able to take all your classes as honors however. The introductory classes for core subjects (non honors versions) can be as large as 200 but class sizes get smaller (around 24) as you specialize further in your major. You can log on as a guest on My Bama to take a look at specific class sizes (look under class schedule)
https://bnrsupport.ua.edu/mybamaguest/guest.html
Yes, most students move off campus after freshman year unless they have a medical dispensation to stay or are part of a specific program like Blount Initiative and opt to stay.
The area around campus is generally fine. I’ve read about some incidents every now and then in the local news but my son has never felt unsafe.