RE: KV Rating on Motors
Yes, for a given number of cells, or pack voltage this is true. I see two ways to look at it...
1) Higher Kv means more RPMs per volt = more thrust/Volt (with same gear ratio & prop).
2) Higher Kv motors have fewer turns = lower resistance = higher current/Volt = more power/Volt.
With a given gear ratio and prop, you can increase your power by getting a higher Kv motor, or by getting a higher voltage pack. So Higher Kv motors can have the same power on a 2S pack as a lower Kv motor on a 3S pack.
I like to overpower my planes a little too, and just use throttle control to keep it "tame". For my foamie, I chose a motor with "optimum" current of 9-11A, and peak of 14A... my batt pack is 12A max (no peak rating, but it seems to handle full throttle for quite awhile w/o getting very warm), so this motor is pretty much the most powerful motor I can run with my batt packs. Another thing to consider, if you've got more power than you really need this... with the Castle Creations ESCs, you can tweak the motor timing, to dial back a little power and current, and get longer runtimes. I figure I'll run mine in the default mode first, and then consider dialing the timing back if I find myself at 1/3 to 1/2 throttle most of the time...