Your horse sounds so much like my mare.
It's not as much noises (except, on occasion), but it's just the tinest things. Like cones in the arena, poles (for jumping), hoses, pretty much anything that was new, or wasn't there the day before (or the last time I rode her).
She was also terrified (litterly - no joke) of jumping. Actually, it wasn't the height itself, it was just the poles. We worked on jumping for a year, went back to the tinest cross rails, then once took her out cross country, and obviously, cross country didn't go well at all! It was only a small log (like, 16inches max).
She's for sale, now. It's really unfortunate since she was my first horse, but I'm glad to move on.
But we actually think it could have been eye problems. We got her eyes checked, and everything was okay. Did you get a pre-purchuse vet check on your horse?
I think it's a lack of confidence for her, with a mixture of horrid training before we bought her.
Does your horse bolt, too? Libby does - it's not a full speed gallop bolt, but it's a quick canter trying to get away from the scary object.
I think some horses are just born spooky, and it's hecka hard to get the spookiness away.
Do you do natural horsemanship?