When I hear music, if it appeals to me I usually find myself drumming to it with my fingers, or singing harmonies, or stamping my foot to the beat. The music club I'm in has a tradition of blurring the difference between performers and the audience, they sometimes hand out tambourines and shakers. I'm a lousy dancer so I don't do that.
I'm only too well aware that musicians move about while they're performing.....I still usually end up glued to the spot when I perform, because I've got too much else to think about, but while rehearsing I sometimes move about more, if it's a song I know well.....though I can easily get carried away and mess up the playing. Many years ago when I was in a rock band, the lead guitarist and I did this thing where we walked off the stage onto the long tables that the audience were sitting at, then we'd walk the length of the tables and back....it was a pre-conceived idea of mine to do that, just for show, and although we accidentally kicked over a couple of beers, nobody seemed to mind (I'd have been furious if somebody had knocked my Guiness over). I also used to walk about on the stage during the lead guitar breaks, which wasn't too hard because I was only playing rhythm guitar and I knew the parts very well.....most of my brain was free to concentrate on a bit of "pretentious posing" as we called it. But being the lead singer, I was pretty much chained to the microphone for most of the time.
Showmanship gets the crowd going more than musicianship does, in my experience. Even if the sound is mediocre, if you slip in a few daft gimmicks the audience will very likely enjoy the act a lot more. I just wish my brain had enough system resources to make showmanship a big part of my performance, instead of just giving them the odd hint of it now and then.