1. 50 toons total.
2. Not at all. Focus on 1 main though.
3. Undead (Forsaken). Horde is win. Depends if you have friends playing tho.
4. No, WoW is on easy mode now.
5. WoW and Burning Crusade are boxed together now, Wrath is still on its own, they all get merged onto 1 account tho.
6. 14.99 I believe (in Canada at least). Time cards are available for retail purchase.
7. Death Knight is a class of character. There's factions, races and classes. http://www.wowwiki.com
, read up!
8. Kind of yes. That's not really important tho. You're months away from good gear. Good Luck!
9. Yes and no, define 'magic'. But not really.
10. Death Knights are a class that you have to have a level 55 (last i played i think) or greater character to be able to start one, and they start at level 55.
11. No, you can get a flying mount though. If you want wings, play Aion.
Check out Wowwiki and I wouldnt post on the WoW forums, they would tear you apart.