Two 225-MGs would work fine on the Phoenix in a pitcheron config, that is what Ed/Skyking recommended on the Shrike and this plane is no bigger than that. On my Phoenix I used a single 645MG on a 4.8v pack and it was great until my wing rod started to rust from the salt air on Cape Cod. It was the oddest thing because only one side became oxidized and it happened throughout the course of one flying session. I suspect that the wing tube is some sort of cheap steel and not brass which led to the rapid rusting.
Regarding the incidence, yes the wing is easier to adjust so I would go ahead and glue the tails on.
One more caveat, the fuse of my plane was as brittle as porcelain, I would lay some more glass into the cockpit or kevlar if you have it.
edit: oops, didn't read the part about how you reinforced the cockpit already, carry on