Thruxton rider

I have a Losi 8ightE 2.0 with a Mamba Max and 2200Kv motor....the set up guide offers low voltage cutoff options from 2 cell to 6 cell, but people I talk to say I shouldn't use less then 4 cell....I have two 3 cell lipos (4300 mAh/25C and 4200mAh/40C) that give me plenty of speed (I'm a basher around the track, not racing), but don't want to hurt the ESC....is the 3 cell OK?

I also have two 2 cell lipos (5200mAh/50C and 5000mAh/40C) that I've wired togther in a series and used that seem to work great, but people say to use in a series the mAh and C ratings have to MATCH. True or not?

Also, a friend bought a used RC8 that he can't keep the motor tight on. He'll tighten the motor, go out on the track, the motor loosens, backs out and the pinion strips the spur. Suggestions.....

Thanks to one and all for any help