Soft pedal, no leaks

Replaced pads, rotors surprisingly pristine, pads little snug on rotor. No problems, for about three thousand miles, took a forty mile back roads loop around town, everything seemed fine, going downhill, applied brakes, jump jump jump, felt in wheel and pedal. Pumped brakes to stop. The jumping was fairly significant but not as forceful as I have experienced. I proceeded, road leveled out. I increased speed in order to brake quick to simulate the downhill load, no jumping, smooth as normal, turned up fairly steep hill so I could come down other side to test again. Jumped again but milder. Was thinking warped rotors but three thousand miles before, when pads were replaced, the rotor were smooth, no scratches or grooves. Pulled in driveway, felt front rims, hot! Both front rims were equally hot. Brake pads were snug three thousand miles before, wondering why brakes would drag now. Checked fluid, full. Waited til next day to try again, I went up and down every hill in the area. Some at twenty mph, thirty five, fifty, sixty. No jumping at all. Pedal had pressure but seemed slightly off. Stopped to feel rims. Both sides cold. The next morning just drove to store two miles away. Pedal still seemed off a bit. On the way back home from store, stopped for red light. Pedal pressure soft. Proceeded to pull in my driveway, Pedal softer, pumped once to get pressure to stop before hitting vehicle in front. Checked for leaks, none, felt rims, cold. Checked fluid level, full. What is going on?
Additionally, about five or six months ago, for about a month, when I backed out of driveway then put in drive, I could hear rear shoes dragging. I would go forward and back a few times and it would stop, until the next time I backed out. Bought new spring kit and shoes, never installed because it stopped after a month. Could that have any effect? So, replaced pads, jumping jumping and hot, slightly softer pedal, greater softer pedal.