Adding cells in the "P" slot is adding capacity, a 2s1P 5000 mah has 5000mah capacity, a 2S2P would effectively have 10000mah - this is the reason its usually done, increase capacity. I use a123 cells which are 2300mah. I built 5S1P pacs and always run a pair, giving me effectively 5S2P battery for 4600mah capacity. I need the extra capacity as 2300 doesn't last too long in my Emaxx.

dont slow down - I'd pm Novak2, on here to make sure you get the smart stop wired right, I don't know how a HV setup works. With the EVX esc, one batt powers the rx, servos and anything else plugged into the rx (fans...). The typical thing is to wire the smart stop to that batt with the reasoning being it is working harder and will be 1st to go to the lvc, so protectinmg it with teh smart stop lvc will protect the other batt as well. With the EVX, you can test to see which batt is which. That's poor on DTX's part, not knowing the burst rating. You know its not lower that 25C, so 30C???

Amp draw is recorded by a few devices such as an Eagle Tree data recorder. I've seen lots of ET graphs showing run time vs voltage and amps. What you notice is there are amp draw spikes that can run a few times larger than average amp draw. I guess these are caused by trigger finger hitting WOT suddenly and the motor asking for many amps. This is where burst rating comes into play, these spikes have to be covered by your lipos burst rating or if you go WOT repeatedly and the burst rating can't handle it, batt will start to overheat. I have an ET ver3, just haven't had time to do much with it, but its going to get used this spring. I want to know what my setups are doing - ET data will also show you how your lipo is doing - voltage drop versus amps.