Well, there might be other conversions out there - I've definitely seen a beta C&C cart dump for either the SNES or Megadrive (Genesis if you aren't european). Perhaps, though I haven't checked, there is a Mac version that would run on the Basilisk emulator (which I must get round to trying some time).
On the topic of crappy conversions, I loved GTA on the PC, but hated playing it on the PSX. Strangely, playing the PSX version now on the pandora is as good as on a PC... just cause the controls are great. I agree that mouse emulation in PCSX-Rearmed would be of enormous value.
Skirmish works a little better than the main campaign in OpenRedAlert but again it isn't without its problems, more than enough to not make it worth playing sadly.
I would also happily pay for the development of this so that C&C can be enjoyed on the Pandora. To get a fully playable and optimised version of the Command & Conquer series on Pandora would be truly awesome.