1.) While I'm not a student, I'm in the same boat as you. I do not have a data plan and am trying desperately to find alternatives to not spending money on Rogers' ridiculous data plans charges...
Your wifi browser may not work without the APN settings present. If it does work without the APN setting while on wifi, keep it that way. There's no way for you to get charged doing that. Its like using a wifi laptop when it's configured like that.
If your blackberry has a lower case 'edge' beside its antenna, your account is TCP data plan enabled, meaning either pay as you go (0.05 / Kb) or mobile internet plans (like $5 for 5MB). If your double arrows are not flashing quickly during a data transfer, its using edge, not wifi. wifi traffic is always quick blips on the antenna.
2.) Yes, inside the address book application, open up the menu, and there will be an option for SIM phone book. Then open up the menu again and select Copy all to Address Book.
Good Luck