The Saito can be a little persnickity until it breaks in some... make sure you are running rich and not lean... that should help prevent the flame-outs...
The canopy? Well I just put alot of small screws in mine... about 22 button head, spaced 2" apart...
Don't change the CG just yet... It's better that you get the feel of the plane first with a few flights AND have the other kinks worked out... It IS satble and can be moved back a good bit, but do so in 1/4" increments until you feel it's where you want it...
Glad to see you got thru the first flights... You're gonna love it when you get more stick time on it and that Saito comes into it's own...