battery questions

[misterzu]

A20 Olinuxino documentation says that li-po batteries are only supported. However its know that li-polimer and li-ion batteries are very similar and can be used instead each other so
1) is it possible to use li-ion batteries instead? I plan to use two 18650 batteries - each 3.7V 3000mAh in paralel - will it work?
2) is it required to use battery  with built-in protection circuit or Linuxino's battery controller is safe enough to use with unprotected batteries? (they're cheaper)
3) what current this device uses from battery? Plain calculations gives (12/3.7)*0.3 = 1A - is this correct estimation?
4) Will battery charging work (even slow) when powered from USB istead of power supply?