Alright let's go for the source for the little blurbs we get about the monsters from Diablo 2 and let's go down the list of ones you listed:
Goatman. You might be right about this one, but even the blurb is unclear so it's very possible that there was a corruption here. However, they say they guard Hell, so unless they transform humans and drag them back on a quite often basis this is kind of out there. And considering the actual backstory to Diablo is that the Demons and Angels pretty much fought themselves exclusively and only discovered Sanctuary relatively recently, even iffier. Actually, nevermind.
Goatman says that it was done by human sorcs. So yeah corrupted fallen humans.
Andariel. I don't know again the text is very open to interpretation. And the
official page for her is even less helpful.
Blood Raven the other folks mention that she's Undead not a demon and she's really the only Rogue we're pretty much TOLD Andariel corrupted so lots of interpretation still. Oh and as for Blood Raven that Wiki says that's her soul, and thus the others likely are too, and since it does in fact kill all the Undead around her as an event that's probably redeeming her really seems logical.
Succubus. This one seems to indicate that they are from hell, so I'm not sure it counts as them ever being human. I just haven't read anywhere where one of the Prime/Lesser Evils can do that much of a transformation. I mean Andariel is supposed to be a succubus yes, but it doesn't say she can birth others is all.
Council Member. This one you're entirely right on says, 'corrupted' so yep transformation could happen here.
Corrupted Rogue. Yep totally counts and you've got something to go with, but notice that they aren't really that transformed. They're just kind of enraged. Though yeah their type is Demon, but that may just be for convenience.
Anyway, this will be the last part I mention other then actual story comments. Again like the story just not sure how close you are to canon. That's why it's always sticky to play in the fanfictionish waters. I think really the story would've been far more interesting if it focused more on Andariel corrupting her host and the struggle there, or maybe since in Diablo 3 we might see a female Diablo, maybe a greater evil somehow survived and you write that story? Just a lot of random Rogue's getting transformed makes it hard to connect with the characters at all.