Sure I can tell.
Initially I came to conlusion (after reading 3 Fading Suns books) that there is very little conversion needed.
The most easiest way to start a campaign:
1. Use SM:P tech levels. Those are good enough.
2. Use slightly modified priest/healer spell lists from Role Master (for priests that are in Fading Suns world)
3. Psionists are ok as they are in SM:P. Maybe some name changes to powers, but those are pretty similar.
4. Careers can be used pretty much with the Spacemaster rules.
5. Different social classes use different technology in Fading Suns (because of the price), so different Tech Level (2-3 lower) can be used to compensate that.
6. Computer related skill development cost need to be doubled or something like that.
Ideally only reading the books is enough. Some monster conversion is needed, but there are very few and mostly it is possible use Rolemaster/Spacemaster Creatures.
Fading Suns is mixture of Star Wars (but there is paper in that world) / Dune (bit more planets and systems) / Warhammer 40k (not as gothic as WH40k is) . It fits very well to SM:P rules.