I have played the hack, and judging by the title, it wasn't what I really thought it to be. There are some game-breaking errors that can be easily fixed by being careful with free items. I'm going to point out the most important issues to fix.

In the message box, "Kaizo" is misspelled "Kaiso". Also, there is cutoff where the slopes meet, at both sides.

You gotta be careful with the key, because it's one of the major game-breaking issues to date, and you can easily skip the whole level by key-jumping, and you can hit blocks with it without needing the throw block. Same thing for the Lakitu clouds.

The buzzy beetle and the sumo brother are horribly glitched. I suggest you remove these, unless you use
YY-CHR to replace these with correct graphics. Also, just a suggestion rather than an obligation, but brown blocks are a horrible replacement for death blocks, so you could use
Skull Blocks to replace them.
And, it isn't really needed to take the bottom spiny way, you can easily break it by walking on the death blocks next to the Sumo Brother.
The cave room... was disappointing. It's just spinjumping spiny after spiny. You could add at least some variety there.

You can keep the throw block by pressing up next to the turn blocks while holding it. It's also a game-breaking factor.

If you really thought of jumping on the three bullet bills, then your idea backfired, because you could jump on the Para-Goombas and Para-Bob-Ombs.

Again, the bottom way isn't needed, since you can walk into the death blocks.

Same thing for this one.
Now, onto the switch palace... it's somewhat decent, though it still has some errors that are either game-breaking or pointless.

Like this one. I don't see the point on that Dry Bones at the top. Also, you could add a bit of a challenge while waiting for the P-switch timer to end, since I can just keep waiting next to the brown blocks.

I don't really see the point of these Dry Bones either. Also, be careful with using that type of tileset, because on Switch Palaces, you can get a free 1-up if you press anything that is an invisible coin block or a simple ? block.

It wasn't needed to use the P-switch at the bottom, since I can still keep the P-switch that I had before, by pressing it and entering the pipe with it...

...and that way I didn't need that P-switch at the top-right.

This level is also very empty, you could at least use some sprites there. And since I got a feather in hand because of the green blocks, you could make it so it's not possible to get it by decreasing the number of green blocks and using
this patch (there is a tutorial on how to apply patches
here).
And also, if you're not careful with the layer 3 water, I can get under the level to skip a majority of it.

Crouching through lots of blocks, especially feather blocks, isn't fun either.

That bottom tile of the door is solid, and it shouldn't stay like that. You could replace it with a solid block, like a cement block. Also, it took me a few minutes and a checking on Lunar Magic to realize that the key was off-screen.
Now, for the castle...

Again, you can skip this part by going above, but the bottom part is that short anyway... I still suggest you block these walls.

This room is so familiar... oh yeah, it's the last room of Iggy's Castle before the boss. Blatant level edits aren't fun, unless you make something in it that at least looks fun.

Glitched background. Set the BG scrolling rate to "None" and "None" and you'll be fine. Also, this boss battle could at least have some uses of the eating block, but I can't think of one right now.
This hack isn't too bad for a first hack, if it is, but these levels aren't that fun, and yes, I have read that expert Kaizo players message you posted. I still think you should fix these issues or restart this hack to make it look more fun to us, especially for the TASers. Also, it wasn't really needed to set the green blocks to be solid, there are the Red and Blue switch blocks that could do the job for you.
Watch
this and
this, and read
this and
this to get an idea of what we are looking for. There are always lots of new ideas to be found, but don't copy them, of course. Good luck on fixing these issues!