Squeaking is what you'd also hear if the motor grinds against the foam sides. It'll quite quickly melt the foam and that'll stick to the bell and "glue" it. At least that's what happened when I mounted it poorly (read: used the supplied glue instead of good glue).
I decided to troubleshoot and tried the ESC from a heli, it seemed to pulse the engine once, then I put it back on the normal ESC and all is working great. Seemed like it needed a bit of a kick to get started.
I have a Bixler 2, but I'm confused by your question. I'm not sure what you mean by "which airfoil". So that we can give you a satisfactory answer, perhaps you could elaborate on your question. And perhaps give an example of the type of answer for which you are asking.
Because you're new here, I'm going to assume that you aren't simply being rude with that question. There is nothing on the packaging or documentation to indicate which style airfoil is incorporated on the Bilxer 2. But simply by "eyeballing" it, it looks similar to the Clark-Y. But if you are really interested, perhaps you should contact Hobby King Customer Service and ask them.
2200mah will fit fine. My old FPV setup on original smaller BIX was (2) 2200mah lipos in parallel and (1) 300mah for vid, rx, and autopilot. Keep in mind that was with a GoPro mounted as well. Granted it was a very modified Bix and a friendly wind to launch into didn't hurt either. Can't remember AUW but it was monstrous. On shorter FPV flights i typically ran (1) 2650mah to motor and (1) 180mah for all the above mentioned accessories.
running a rctimer 2826-6 motor I could squeeze out 25-30min flight times. Keep in mind the trade off between weight and lipo capacity starts getting more difficult the more the press the airframe your using. Been a couple years but if I ran (1) 2650mah i could comfortably cruise the plane at about 7-9amps....if I upped to the (2) 2200mah yes i increased capacity but traded cruising apms....something more like 12-15amps. Everyone ultimately finds their "happy spot"....mine was to give up FPV altogether lol