I don't have an account there, and I can't be bothered to make one, so I'll just answer your concerns here.
1: As far as I know, no. The only hypothesis I have is that using 7nm Ryzen could fix the issues, but I have no way of testing unless I get a 7nm Ryzen part. There's also the possibility of getting it working by downgrading your BIOS to or near the release version with a CH341A or other flasher, but that could result in a bricked board if done wrong.
2: Kinda sorta,
https://board.eclipse.cx/viewtopic.php?t=345
3:
https://board.eclipse.cx/viewtopic.php?t=342
4: I have been unable to get NVMe drivers working, however there are working USB 3 drivers at the bottom of this post
https://board.eclipse.cx/viewtopic.php?t=309
5: As far as I know, no, however try searching win-raid or MSFN for info.
6: I think someone posted something that added TRIM to Vista on MSFN some time ago, but I'm unsure about that. I do know that most modern drives have hardware TRIM, so I don't really bother with adding it. All it really does is improve performance.
Maybe there are some eMMC drivers somewhere, I could look, but I'm not sure.