1. I have a similar experience than 403Forbidden, no bans occur Ip based with world of Warcraft unlike all other games I botted.
2. Wow runs fine in a VM, but you have to set to 800x600 low graphics to have 20fps, depends on your CPU and GPU. I have good performances with VirtualBox and VmWare Player
3. No problems, you can run 5+ accounts with no problems with a decent computer, they do not seems to IP ban, computer redflag or something else.