Nokia 5.1 has an ARM Mali T-860 MP2 GPU. It is a dual core GPU and GPU frequency is 700 MHz.
Nokia 5.1 has a single channel 3GB RAM. The RAM frequency is 933 MHz.
No. Nokia 5.1 does not have the front camera LED flash but it does have the display screen flash.
Yes, Nokia 5. 1 does support OTG.