Sound like the valve is a likely culprit. Easy to take apart and inspect the spider or wagon wheel gasket. It will be obvious if this is damaged. Something else to look for is water leaking out the waste line when in the filter or recirculate positions. If you do a quick search for vari-flow you should find lots of info. If not, post and we'll guide you. As for the handle being hard to turn, could be the shaft is gummed or the O-ring shot. Again, easy to take apart.
Al