1. not sure
2. I have 12s setup too, you should NEVER EVER go below 3,5 V per cell (meaning 42 V), and possibly not below 3.7 V, there is barely any energy left (like 15% depending on C) but you shorten lifetime significantly
3. yes, performance goes down by a lot, bike goes lazy around 46 V (maybe tweaking the drive in app could help, had no luck so far but havent tried to for over 6 months now)
4. yes, this should work as long as all the batteries are same, you charge each cell to 4,2V and if all of them behave the same its good to go - if there is a weak cell, it will weaken the rest too
5. and obviously I mentioned this in 4) before even reading don't use different batteries together, they behave different too, it would work but I seriously doubt anyone would recommend this...C rating depends on mAh and "quality" of the cell, better cells can charge/discharge faster, if you have 10 C constant you can use 3000 mAh battery for 30 A drive but expect no more than 10km range
6. no its not, the discharge rate of batteries is not linear, its a curve and if the drive wont realize that some of the batteries are already <3.5 V and some still 3.7 V eg., again - it would probably work but show me someone recommending this
7. power is a matter of voltage, amperage = distance, 5000 mAh = 15km 10000 mAh = 30 km (approx)
Simply: for the 48V go for 13S setup, the bike will run faster for a longer time. Btw: I run LiPO with bulk charger +
BMS (not like you need
BMS all the time, batteries will stay balanced for some time but the
BMS of mine protects over/under voltage too)