RE: Charging a flight pack
The initial C/10 charge (50mA for 10-14hrs) is to settle the packs in. Cycle them 2 or 3 times by discharging at, say, 1A, then do your slow recharge at 50mA. After that you can charge at a faster rate every time. The 2A (=4C) sounds just a bit much - I know those are good cells, but they may be happier at about 2-3C max. (1A -1.5A).
Cheers, Phil