#1
I am planning on changing from Edge 3's to Edge Pros. But this might be expensive since I am planning on getting a good amp.

Whats the difference between these? The Edge 3's kind of go out of tune when using the whammy unless the locking nut is really tight. I heard the Edge Pros are better but I dont know why.

Also I want to be able to dive up. I can only dive about a whole step on the high e.
#2
^^

yes it's a good change...
given that the posts are of the same measurement...
(I've heard that the Edge III have different post measurements)

what's the difference?
the difference are the materials used and how it was produced...
so the difference is BIG...