Marina Slim Filter S15 for Style Number 60

I have a 5 gallon filter with African Dwarf frogs and a betta fish. Is this filter appropriate?

a part of the electric cord above the motor is submerged when i fill water to the fall out spout is this normal? did i do something wrong?

so im planing on getting a 5 gallon tank for guppys and a 10 for plattys and crown tail betta would this suck up any ones fins?

How many gph is the marina s20?