1. Turn the reverb knob to zero. What you're describing is 100% normal for these amps, the footswitch in fact does not "activate" the reverb, it de-activates it by shorting the reverb signal to ground. If for some reason turning the reverb knob to zero doesn't turn the reverb completely off (it should), then you could either unplug the reverb tank entirely or make a shorting plug to leave in the reverb footswitch jack.
2. I don't know for sure, but you tube video demo of a Kustom 88 shows the "sustain" being deactivated by shorting out the cable connected to the sustain jack. Guy in the video says you need a "normally closed" sustain pedal "...like those used on Yamaha pianos."
"I have no actual information, just what the salesman told me."