This brings back some memories. That system is definitely underpowered for playing Jedi Outcast (at high res/settings). A more time appropriate high end machine would've been a i850E/Northwood-B (533 FSB) or KT333 chipset + Athlon XP (Palomino/Thoroughbred). The GPU would've been a GF Ti4600 or GF FX or Radeon 9700.

Not really sure what the hell the "minimum" settings would be playing this at.

Some benchmarks:
http://www.anandtech.com/show/970/10

Understandable, but for the yavin levels to be utterly 100% unplayable at any settings despite the game otherwise being fine makes me question things.

You shouldn't be having those issues at least with JO, back in 2006 I played through the entire game on these specs

Pentium III 933
Intel 810 unknown board
256mb PC133
Geforce 2 MX 200 PCI

It was playable, you should be more than playable