I originally thought that Dusknoir had bad Attack, but 100 Atk isn't too shabby. These moves you have on it are powerful, and do have quite good type coverage, like you were going for. I don't think you would miss out on too much by getting rid of ThunderPunch, since it's only effective against Water and Flying (Flying is covered by Ice Punch). You may want to replace it for a STAB move, like Shadow Punch to keep with the consistency of punching moves. And of course, there's always the option for walling if you don't like Dusknoir attacking for whatever reason.
Best of luck and I hope this helps!