Could it be his teeth?

This may be a little longer then intended, just a warning but i'll try and make it short! Ok so it was June 26th i test rode a gelding and he went fine, i did flat and jumping about 2'6" he rode perfect. We went back a week later but i didn't do much with him, he was sore from a recent hoof trimming. July 17th we brought him home so it was the 18th i rode him w/t in a halter with someone leading me (we were careful he was a new horse but none of my tack was there). Later the same day we found one of my old bridles and found his size bit at a store so i put that on him on a loose rein (basically on the buckle) he went fine, when i tried taking up contact he was acting a little silly he would occasionally chew on the buckle it was constant chewing and some flipping his head when i took up contact. still 3 other people (2 of them beginners who i had to lead) plus me rode him and he was ok. the the 19th we found his fear of storms i didn't get back on until the 22nd when i had my new bridle he was nervous in the front part of the property we took him around to where he couldn't see the barn and he settled down letting me and a friend ride w/t on a loose rein still kinda chewing at the bit a little but at the trot you could feel he wanted to run. long story short he did some funky stuff with the bit, took off galloped across a road towards the barn and stopped when i jumped off in front of the gate. we thought he was buddy sour already but when we turned him out he went to the opposite side of the field of the other horses (we did bring him back across the road to where he bolted but he wouldnt go ped a foot of the opposite side we swapped the bridle for a halter and walked him back where he was still wound up but ok (there was a storm rolling in he might have sensed like i said he has a fear of storms). we went back and got on the 24th i saddled him but couldn't get on him due to a girth problem (he refused to cross the street to the riding area with nothing on his back and just a halter and lead until my dad finally got him then he crossed willingly every time after and was fine). we came back the 25th with a new girth saddled him and i got on him but with a halter and lead rope my mom led me and he did well responding to my voice command "whoa" and sitting back from walk to halt, that afternoon we put the bridle and saddle on and i got on he was wanting to run and flipping his head alot and chomping at his bit he kept stretching his head down my mom thought he was going to roll, and when i got his head up he kept breaking a trot and you could sense he wanted to run. i haven't been back on since i have been on the ground. the vet is coming to float his teeth next week, do you think based on what i described that might fix him or do you think it is something else? wow ok that was long anyone who read it and can answer thanks a ton!