Okay, wacky problem 1 solved, somehow I managed to have two versions of lein installed.

Thanks to everyone's help, I was able to get a working setup using lein-tools-deps and Cursive on Windows, with clj installed on WSL. It's pretty hacky, but I think will tide me over until the tooling solves this problem in the right way. See fork on lein-tools-deps at https://github.com/ComputeSoftware/lein-tools-deps. Use at your own risk 😋