I'm looking over the rules for the older models of power armour, and I've noticed that many of them give a conditional bonus to Fellowship (a Charactersitic bonus, not a bonus on a Test). These are often noted as "in dealings with Space Marines" and this makes me wonder: does this include renegade (and even Chaos) Space Marines? I suppose it's possible that even these guys have some respect for the old threads, and I imagine that it might help with Decieve, but for most other Fellowship skills probably wouldn't really matter much.

I think seeing it on the heretics just reminds a space marine how they've fallen from grace so long ago, or can help to serve as an indicator how old said heretic is and how experienced they are. I imagine a heretic in mark 1 armor as a huge Korn Beserker that has muscles the size of medicine balls.

So I might say it applies fear.

As for renegade ones? I'd say it might offer them some ability, perhaps to counteract the stigma of being a renegade chapter. Depends on which one you'd pick. So yeah, I'd believe it.

I thoughts are that you reverse the modifier with Traitor legions. ( A +10 bonus becomes a -10) Of course, you would need a GM's ruling or the group's ruling.