I took the LSAT at a testing center and I also tend to fidget a lot, including many of the things you mentioned. I think their main worry with you fidgeting is that you might be copying off something and trying to look around the room. Testing centers are set up in a way that this is pretty much impossible since you can't take anything into the room with you, and they had no issues with me fidgeting in my seat or anything. Only thing that is a big no is making noise/talking. I think you will be fine! You got this!