imo, yes, it's too much. I won't say what works for you, but there is no way I'd want to try to coordinate that many different classes. Others have so maybe you could too, but you asked, so there ya go.

As far as setting up the key layouts and whatnot for a keyboard broadcast, this is the hardest part of getting it all up and going, to me at least. You really need to just sit down, figure out how all your toons are going to work together (very hard for 4 diff classes), and lay out the keys that make the most sense to you given that. There really is no shortcut here, just gotta bite the bullet and spend some time on it.