I could quibble about some of the things you're doing (or, as I said maybe I'm missing or misunderstanding something) It doesn't really matter because it doesn't change the end result.
No matter how much you capitalize things, vague declarations don't mean anything. You created a complex character with a lot of options and now you're complaining because you have a complex character with a lot of options. You also want a completely different game that works by a different set of rules and assumptions. I don't see that as being a satisfactory option for most people.
I've told you what we do to speed up the game. If that's not applicable, it's not. If high level play takes too long for you perhaps there is no alternative that will work.
But, that's the thing. This is not a complicated character. This an Open Hand monk. That's pretty basic. A straight Battlemaster fighter could easily have just as many things to do in a single round as the monk. A caster, plus pets/summonings, can also easily have just as many actions that need resolving, again, sequentially.
And, let's not forget, the monsters are just as complicated. Again, straight from the Monster Manual - CR 16 Githyanki Dracomancer. Here's the stat block in spoilers to avoid cluttering the post:
Now, that's a single monster. It has 3 attacks, each dealing base + fire damage and inflicting the frightened condition. It can also Misty Step as a bonus action. That's about as simple as it gets at that level. Surprisingly, no resistances, which is nice. But, you still have to make 3 attacks, deal damage, dealing with various resistances that the PC's have, plus adding fear conditions, plus a bonus short range teleport. And that's only one critter. Typically, 16th level party is going to face this plus probably two or three more baddies, at a minimum, easily a pair of CR 8 Githyanki knights each with 3 attacks, one of which can be a telekinesis spell, plus a bonus teleport.
And this is a bare bones, no frills encounter for a 16th level party.
So, no, I'm not being "vague" at all. I've been really, really specific. Heck, I've offered solutions to the problem in this thread: I posted my Mob rules which have greatly increased the pace of encounters. I've talked about "Legendary" characters having separate Legendary mechanic like Legendary damage akin to MDC from RIFTS where high level characters don't track damage from non-legendary sources - they either just kill the baddie, or ignore damage under a certain threshold. The Threshold damage rules could be used here to speed things up. Instead of characters having 4+actions in a round, they get one or two, similar to how 4e handled things - lot's of burst and blast AOE effects to simulate having multiple attacks.
In what way am I being vague?