There were some fixes to media search in 2.1.5. If you can’t upgrade, try changing your media search settings to not exclude any volumes. Well, maybe exclude the Main HD since it takes so long. Also there is a “skip this volume” button in the search progress window so you can override the lengthy volume.
I recommend that you buy an external USB drive and back up your system to it (with Time Machine or Carbon Copy Cloner) so you can get back to where you started in case of a problem.
Then, install Snow Leopard, but don’t let it update to 10.6.8 if you have any NTSC-601 media in the Media 100i codec. After that, you can run the Media 100 Suite installer.
Media 100 Suite has not been qualified with any Thunderbolt AV card, so if you need a hardware solution today, you need a MacPro (with AJA, BlackMagic, or Matrox) or the 17″ MacBook Pro (Matrox PC card slot).
That’s plausible. Also, Suite needs the file to support resource forks, which some file server protocols don’t allow. If you can tell us what kind of server it is, maybe someone on the forum knows something about it.
If the file you’re importing is in a codec that Suite supports natively, it tries to add some data to the original media in-place. So check your permissions there, or check the “import media to the selected standard and codec” in the import dialog.