1) Yes you can but typically you have to to get a butt ton of community service hours to "prove" that you plan on making this your permanent home. I do not know much about the process being that I wont be changing my residency
2) I am surprised, we are incredibly close!!! we have multiple class GroupMe's revolving around fun socials, memes, or study materials that we have all generated. Additionally each and every one of my classmates look out for each other to make sure that we're academically and mentally good with each passing week.
3) Could you clarify with the "pros/cons" question in regards to if you're asking about the school, field, etc?
4) I love what my old mentor said, which is that Treat the Interview like a date!!! Have fun with the whole experience, don't be afraid to make joke or to disagree with a statement, and always remember that it's just as important for you to love them as they love you. I would much rather get rejected to a program that I would not be happy being in then end up saddened for years to come. In regards to actual tips, be friendly with EVERYONE (you'd be amazed how far a smile and sincere compliment can take you in life) and DEFINITELY WRITE A THANK YOU LETTER. I personally made mine very personal (saying thank you and 2-3 sentences for each person that i remembered) following the interview, and I am almost positive it helped my case.