LMV324 benefit of double feedback?
The internal feedback is to stabilize the amplifier so it does not oscillate and has reasonable phase margin for any external gain. 

Typically with an op-amp the (compensated) open-loop gain will start to drop at around 10Hz and will drop by 6dB/octave (single dominant pole). The series resistor will have a small effect- the gain won't drop as much at frequencies approaching around 1MHz.