I know Frankie hasn't knocked alot of guys out, but he was fighting undersized and was able to drop Benson and Grey who are HUGE LW's. I think if Frankie lands a shot like he did against Benson or Grey it might be night night for Aldo.
As far as grappling, im not sure how good Hominic is...but Frankie is at one of the best BJJ schools in the nation with some of the best instuctors. If I remember correctly Hominic had Aldo in a DEEP armbar, I don't see why Frankie couldn't put Aldo in that same situation.
I think an Edgar finish is very possible. 
Aldo isnt Maynard or Henderson, Edgar wont land any big shots on Aldo