I think it would be better if they weren't armed. Giant weirdos with acid guns is a little cheesy, at least, in my book. Maybe instead, the Cremators could come and collect the body, and bring it somewhere for disposal?

Benefits would include providing Civilians a little bit of a show, allowing some passive roleplay for those playing the Cremators, and hauling their body off to places unknown would add to the enigmatic demeanor of the Combine, instead of adding more to the brutal side that we would see everyday in the CCA and OTA. It could also provide a neat opportunity for possible resistance roleplay: while a unit stands guard by a corpse waiting for Creepy-Cremator, it would be an ample time for an ambush.

the whole point is that theyre SUPPOSED to burn the bodies
1. they're clearly too weak to carry bodies
2. the acid gun is part of the model (hl2 beta snpcs, could use that) so theres probably no way to remove it, its obviously not able to be used, hence the RP part, the cremator would do the /me's and /it's then use a remover tool to get rid of the body (since the body is disintegrated)

I think there should be a cremator faction in CG HL2RP.
What are cremators?
http://half-life.wikia.com/wiki/Cremator
Of course you would need to make an application, but that's fairly obvious is it not?
The whitelist would be mostly PassiveRP, because as the wiki says they are basically janitors but with big ass flamethrowers.
They would only be able to use their Immolators in SELF DEFENSE, as they are clearly not made to fight.