Nice to hear it works!
Your findings coincide pretty well with mine, except for the vertical sync part. I'll have some testing to do to find out why it screws the nav map on my PC. Still it's nice to have a stable framerate and yes, no lag
It's weird that this works, but renaming the sh4.exe to anything else(like fear.exe, which works well with many other "non crossfire" games) does not.