A day late and a dollar short; but with regards to the connection i sometimes have issues with my internet connection in Stormwind/Ironforge. So as a test, you could just wait till Friday at 5pm, make 3 trial accounts, log all 5 in and if you can run around (insert perpetually overcrowded city for your server/faction here) you'll be fine. You'll probably be fine though as everyone says. (I suppose this would also be a good way to test if your comp can handle the extra instances too. ). Its the huge huge crowds of people that do me in. People/my chars start ghosting everywhere and /follow is constantly breaking. hehe. But only at peak times. Never have issues except at the AH in those two places.

BTW, I love the names.