I would permanently mount the stabs, they are not the most secure setup. I definately wouldnt stand over the tail when you run up the engine.

From what I've seen the wing tube is an odd size and nobody has them.

I'd run the stock gear before you buy new gear, might as well make sure yours breaks before spending the $$ so far mine is ok.

The 2100 batt should be fine I'm running a 2200 and I'm also running all digitals so your analog servos you should be fine.

I hear the 220 saito is a shaker so make sure you locktite everything... the plane flies great though.. you'll love it.