I have some questions about Iphone 4?

[Quietvacation106]

Hi There
I have 4 questions about Iphone 4.I'm getting one pretty soon so I have 4 questions.If you have some time please answer
1. If I buy a locked Iphone(I mean the ones that you can't put sim ,can I still go on web,download apps,play games etc?.I don't care if my sim won't work on iphone .I have another phone for my sim card.
2.I heard that Apple is going to fully unlock all Iphone 3 & 4 in 2 weeks.Is it a rumor or true?
3. What are some good apps(games,etc) that I can get on my Iphone? and please list them and tell me why do I need them
4.Is 16 gb enough for a teenager ( I;m 16 years old,I want some good apps on it.photos and music.or should I get a 32gb.
Thanks so much for your time.