Just call and ask for the plan on your account. Tell them you bought an unlocked phone online and need to register the pin as well. Hopefully the previous owner didn't register the pin or de-registered it.
edge means no bb data plan.
EDGE means bb data plan.
For #3 if you go to the options on the dialing screen you should be able to see the option to fix that.
Prior: BES: 7510, 7520, 7290, 7230, 7130, 8220 (No Data Plan), Droid Eris
Post your question on the forum, don't PM me.