I want to run everything on that list except for the servos from the 5v line going through the atmega.
Give it a shot if you wish. I still don't think it's real pratical. What are all those devices going to mount on, some kind of mother board, breadboard,etc ?
If so there would probably be room for a TO-3 size regulator to power everthing mounted to it, that way only Mega signal lines and a ground would have to wire between them.
Lefty