stepping in with the right hand should you twist the rear foot?

If you were to throw a stepping right hand would you twist the back foot or just drag it with you as if you were moving in with a jab?

You have to pivot the foot to turn the hip; even if you are really lunging in with it, your weight moving forward, you'll end up turning the foot.
On a related note, you aren't doing yourself any favors by 'dragging' your right foot in any case. When you step in with a jab, you need to be pushing off the right foot, and bringing it up sharply.

Thats what I was trying to say by dragging(I did an awful job of explaining it tho), but thats my question if I push off my foot it doesnt really rotate that much. Is that little bit of rotation all that is supposed to have it or are you really supposed to pivot like you are stomping a ciggarete into the floor like a normal straight? thank you.

A little bit, to get the hip turned. I don't know how you position your right foot, but it is advantageous to keep the right toe pointed at your opponent. It takes less rotation to get your hip turned.