No. Comio C2 has a dedicated MicroSD card slot. You can use 2 sim cards and 1 memory card at the same time.
No. Since Comio C2 has 4000 mAh big battery and to avoid heating issues, company has used high quality Polycarbonate body.
Yes, Comio C2 does have the memory card slot.
It takes about 4 hours to fully charge the Comio C2. That is because it has huge 4000 mAh battery. If you use any good quality fast charger - the charging time can reduce by almost 35%.