It depends on what you are doing on your Phone. Different Deals will work better for you than others.
NO
You would need to have a blackberry plan if you wanted to use things like BlackBerry internet and messenger etc.
It is as long as your services includes a full data plan and messaging plan.
Yes as long as you have a data plan with blackberry
Blackberry and the carriers require you have a data plan for all Blackberry phones.
You can get a data plan from a service provider such as Verizon.
blackberry
I have a Blackberry Storm that is only offered by Verizon. I have unlocked it and am using it on ATT. The best way to do this is to go to www.crackberry.com and go through some of the disucssions there. They have lots of unlocking tips and links. The best one I found was www.berryology.com. This website is all about unlocking Blackberry phones.
To get Blackberry service, you would have to register the device for a special Balckberry data plan.
Yes, you can download music to a Blackberry online if its in your plan for web browser.
I do believe that the Blackberry Bold 9780 is a very good choice of phone. It's capabilities are vast and various, and the plan is good as well.I suggest that anyone should try the Blackberry Bold 9780 for themself and you be the judge.
Before you can use internet on an Blackberry phones, you would need to register the device for the special Blackberry Data plan. Any regular data plan would not work on Blackberry phones.