If you don't want dirty pants legs, use leg clips/bands, and lube with White Lightning. You could put a chain tube on an EZ, but it isn't designed to use one. If your ankle is in the chain all the time, maybe your feet are pointing out instead of straight ahead? You might want to use Knee Savers (pedal extenders.)
All the other stuff is adjustment-related. The guy you bought it from is incompetent as a mechanic. Find a competent one.