No. During our review did not find any major heating issue. However, since the mobile phone is made of Alluminimum Alloy body and has got huge 4000 mAh battery - you may notice some heating issue while charging.
No. Gionee A1 Lite is not a waterproof phone. But it is made of Aluminium Alloy and hence you may get some protection against damage.
No. Gionee A1 Lite has 2 dedicated sim card slot and 1 dedicated MicroSD Card slot.
Yes, Gionee A1 Lite does support OTG.