A favourite of mine is to "confiscate" hats and such items. Especially lightsabers! "that's a illegal weapon sir!" I also like to "sneak up on people who stand off and watch the fun from a distance. Scares the bejeezus out of em.
Anyone in a hooded top immediately becomes a jedi suspect and treated accordingly
Bag inspections are always good fun too, accompanied with the usual "you're cleared to procede, move along!"
The armor question happens a heck of a lot, "it's imperial issue" works wonders. I've also been asked where I'm from a couple of times, to which I answered "a galaxy far, far away" raises a smile
High fives and handshakes are good for engaging nervous kids
Another thing to do with the photo op's is to inspect the photo taken and give or deny clearance
Just have fun with it dude, you can't script to much, it's crowd interaction that makes a troop and most of the time you just have to think on your feet. Just stay in TK character and roll with it