I have thought of a similar setup, only with the pump/vacs on top, so you could get to them without draining the tanks. The only problem is that puts the drain port way below bucket height.
It's a safe bet you won't be dragging this monster up any stairs...
You can get a short 5 gallon bucket or it is pretty simple to add a pumpout. A $40 sump pump would work fine. You would want to filter well before you get to the waste tank so the sump pump isn't trying to move chunks. It will also help if the sump pump is set a couple inches above the bottom of the tank.
someone has poor trigger control.
you anticipating recoil and forcing the muzzle down as you jerk the trigger?
It should be a smooth "press" on the trigger all the way thru while focusing on the front sight.
Don't forget the "follow through" after the shot too
you mashing the shutter button on that camera with your elbow?
or is that porty moving at 20 mph.....