Reaver said that he's waiting for the new DX11 version of CXBXR to be ready. Until then, unless someone else decides to work on it, it’s unplayable. The CXBXR team is also working on getting the Original XBOX version playable.
The issue with CT3 is the headlights (Courses 2 & 3), which make them unplayable—something Reaver will need to look into.
I don't think that's possible
The new CXBXR TP build has been merged with TP, so you don't need to be a sub to play it.
New games
WMMT 1 (Japan)
Ollie King
Crazy Taxi 3 (might have severe graphical issues. Haven't tested the public version)
Edit: CT3 still isn't working. Not sure when/if it will be playable