Accumulator is a "spring" basically, the larger the spring, the fewer the cycles the pump goes through, but of course it runs longer when it's on.
Surely your pump isn't 10 ft above your tank as was posted?
If it's sucking air, it could have what amounts to an air hammer, which is noisy, it could also be a partially clogged dip tube, clogged with lime. I've had that and water
flow was reduced, pump was noisier and pump run time was longer as pressure build up was slower. Easy to check, just pull the dip tube