Hi. I'm working on a bathroom redo. (This is long, sorry.) I have it down to the studs and subfloor. I have a few technical questions. I'm doing it myself (capable female here) with the help of my brother and lots of reading. Even though I'm doing it myself, I want to make sure it is done correctly and won't leak. I have looked everywhere trying to find if I can use hydro ban on the schluter tray. I can't find anything in any of the forums. I know from all of my reading, most say "stick with one company product and go with it". I'm trying to find an alternate method for my shower floor so I don't have to build a mud bed. I have already bought some hydro ban. Here is what I would like to do, but will it work?:
My shower is on a corner of my house sitting over a basement crawl space. My subfloor is only 1/2 or 5/8 inch plywood. I was planning on putting another 1/2 inch on top of that. (Isn't minimum 3/4 inch?) Either cbu or wood.
I would like to use the schluter tray (thinset to wood floor), apply thinset on top to fill holes and level it, then apply 2 or 3 coats of hb on top of thinset, then tile. Will that work with those 2 different company's products? I know there wont be the 25 year warranty, but thats ok if it will work. I just don't want a leak. Thoughts? IF that works, then:

Drain. Will the flanged hb drain (my preference) work/fit on the schluter pan, or do I actually need the kerdi drain? I couldn't find that information anywhere either.
If I build the mud pan and put hb on top of that, will a foam curb work, or should I build that too with 2x4's?
With the mud pan, do I need to add anything to it besides the sand and cement? I've read about laticrete's 3701.

I am not planning on tiling the walls. I want to install cultured granite panels on top of the cbu walls. So I will have tile on floor, granite panels, accent tile above panel, then additional panel next to ceiling. I also want to put in a niche with the accent tile. Sequence? Do I tile the floor first, then set the panels on top of the floor? Or set the panel on top of the shower pan, then tile to the wall?

I'm going to build a bench as well. Do I have this right? Frame, 3/4" wood top, 1/2 inch cbu, hydro ban, whatever top I choose to put on it? Then the same on the front- My question here is sequence again. Do I cut cbu to length of subfloor, then put tray against the cbu, tape it, then hydro ban it, or only cut cbu to top of pan then tape and hydro ban?

I know laticrete has the shower pan as well with the drain built in, but it's $400. I'm trying to shave costs where I can. I actually called schluter to ask them, and the response was "I don't know".

Sorry for all the little stuff. I appreciate any help anyone would like to offer.
Jen