I have been reading and researching a lot and have come up with the following plan to finish a 600 sqft basement. I am looking for some feedback and / or advice on how to improve this plan. Minimizing the space lost for floor and ceiling is a premium as we have a low roof to start.

1. Use closed cell spray foam for the rim joist and walls for insulation. Do you need to insulate the partition wall at all that divides the room in half?
2. Use metal studs for hanging wall material.
3. First question is what type of wall is best for a mold and moisture resistant wall surface? Possibly T1-11 siding??
4. .5 - 1 inch XPS board for the floor with cork flooring over this. The entire basement has a drain screen around the perimeter which was done by a waterproofing company before I purchased the home.. Can this flooring be placed over top?
5. Install hot water baseboard heat that can use existing natural gas boiler.
6. Add a commercial dehumidifier to help prevent any issues.
7. Looking for the thinnest ceiling possible to minimize space without just using paint. I was looking at CeilingMAX, but not sure if that is very good.

thanks in advance for any help!

A non paper-faced gypsumboard, such as DensArmor Plus, will work well in a basement. However, I have never put anything other than standard drywall in basements with never a problem as long as you provide for dehumidification and washroom/laundryroom exhaust ventilation.