Hmmm…I don’t envy you. I had a horse (a crazy horse) who had a similar reaction to things he disliked. If I wouldn’t let him bolt, he would balk. I distinctly remember trying a Happy Mouth pelham on him one day (to maybe gently encourage him not to bolt to fences). I had one or two fantastic fences, but then he realized just how much control I actually had and grew roots the next time we came out of the turn.
In that case, I didn’t get far, but the horse was, truly, one of the craziest horses I’ve ridden (and I’ve ridden some loony tunes).
This behavior isn’t as “new” as you state in your OP, as it sounds like he’s done it some at home. I would seriously consider a good lameness exam. It isn’t terribly unusual for a horse in pain somehow to want to bolt at the jumps. Nor is it unusual, when they are told bolting isn’t acceptable, for them to balk and grow roots.
And I would definitely not allow him to be “bossy”. That’s unacceptable. I would also make sure he realizes that not going forward, on any occasion, is not an option. If you put your leg on, his reaction should be “Yes, ma’am! Right away!” NOT “Meh…I’ll think about it.” Or “EFF YOU.” Don’t wait for it to get to the point of growing roots. If you close your leg at anytime and he’s not quick to respond, I would back it up swiftly, firmly (but fairly) with a good, stiff tap-tap from a whip. No compromise.
And more outings. Being overwhelmed is a good reason to revert back to your naughtiest habits.