No. Tecno Camon i2 does not have the fast charging. It comes with 1.2Amp output charger.
Yes. Tecno Camon i2 does have the dual rear camera set up. It has a 13MP and a 2MP rear camera.
Tecno Camon i2 has a dual rear camera set up. The 13MP rear camera has a f/1.8 aperture while the 2MP rear camera has an aperture of f/2.4.
Yes, Tecno Camon i2 does have the OTG support.