1. I use isboxer
a. Dont need expensive keyboards but an extra monitor is helpful if you have more than two toons. This is for making sure follow didnt break, taking flight paths, quest turn ins etc.. It partitions your screens however you want. You can have one screen with 4 small slave views along the bottom. Or you can have a second screen with a 4 way grid for the slaves there.
b. it has native support for click aoe's. clicking on the spot on the masters screen will activate the aoe on the same spot on the slaves screen.
c. easy to learn hard to master. crawl walk run. you can use it for multiplexing (pushing the same key on other computers). Its actually fun tweaking your setup from time to time. Level up, gain a new spell. Change your spell lineup to integrate it into your team.
d. the programer himself gives live tech support chat. i've asked alot of questions.

2. Only need 1 wow folder with isboxer. isboxer will launch all 5 of your accounts for you. If you have any settings set wrong it will even ask you if you want to fix it for better FPS.