Bathroom Refurb - Best Practice Advice Questions

[Superflo]

I am in the middle of refurbing my daughters ensuite (3mx2m) and was wanting some advice on best practice for a few things. I have stripped the bathroom back to stud work and plan to replace the chipboard flooring (22mm) with something? plus 6mm Hardie backboard on top, I plan to do the walls around the shower in jackoboard and the rest of the walls in plasterboard, the room is a jack and Jill and therefore has no outside window. looking for some advice on the following:-

Whats best to replace the chipboard flooring, 22mm - 18mm WBP / Marine Ply or something different, I will also add 6mm Hardie Backer on top. Planning to tile walls and floor.
Would you also fit the shower tray over the top of the Hardie backer board or just ply and Hardie backer around the shower tray?
What would you use for the remaining walls? use jackoboard or moisture resistant plasterboard.
Any ideas on insulation for both floor and walls?
The room has no windows, what's best ventilation system to use, some form of in line system.

many thanks

 

[Swwils]

Schluter kerdi board for all.

The difference in price will be worth it in time saved and less mess created. Plus they are light so no lugging cement board around.

 

[Superflo]

Schluter kerdi board for all.

The difference in price will be worth it in time saved and less mess created. Plus they are light so no lugging cement board around.

For the floor, I assume this would need to go on top of ply or chipboard?

 

[Swwils]

Depends. Most bathrooms will have UFH with something like BEKOTEC THERM.

 

[Superflo]

Depends. Most bathrooms will have UFH with something like BEKOTEC THERM.

Thanks I’m not planning to fit UFH.