That was probably poorly chosen phrasing. And I apologize if you are offended.
Don't worry about it. 80-90% of my offense was caused by having gotten 4 hours of sleep, followed by 8-9 hours of learning new skills (workshops are fun, but not when you forget you're taking them until the evening before they happen, and you have other stuff you need to get done before then!).
Of all the things you suggested Goodman Grey is the only one known to be a shape shifter and he can't or didn't use magic.
True, but shapeshifting accomplishes the same thing as magic when it comes to disguising yourself as someone else, which I believe is what is being discussed.
I can spell genoskwa either, but he doesn't appear to be a shape shifter.
No he isn't (apart from the Denarian thing) but he can at least use veils (which are a subset of illusion magic) undetectably. Based on this and his skill with earth magic, I figure it's a pretty safe bet that he could learn to use other illusion magic (and thus gain the ability to impersonate others) undetectably if anyone could give him a good reason for doing so.
Molly has never been shown to assume a different outer shape, she's the invisible girl and a copy monster.
Molly's illusion powers can explicitly make her look like other people. She is also less prone to hexing things than Harry, and we know that even Harry can suppress the hexing thing for a little while. Thus, I figure that an older version of Molly has something like a 90-95% chance of being able to suppress hexing and other magic-detecting effects (maybe the other magic-detecting effects aren't suppressed, she just veils them from notice) while using illusion magic.
The rest never show up in the books, or if they did I missed them.
They don't show up.
Jenny Greenteeth sits in for Georgia at Billy's wedding, Billy never catches on.
But Billy, to my knowledge, has never shown any particular ability to detect the supernatural (except
maybe smell, and is also understandably distracted by the wedding.
In Summer Knight Harry takes some time to catch on to what Mab is.
She's Mab, Harry's a wreck, and he
still catches on within five minutes or less.
And both Mab and Lea have used their magic to mimic Molly and random people.
True for Lea, but when did Mab do it?
Listens To Wind is the only human in the books to shape shift and use magic.
Well, technically the Alphas all shapeshift due to a spell, so they are using magic by definition--but I get your point.
However, weren't we mostly talking about illusion magic? I'd thought shapeshifting was just an alternate option for that.
The Whites don't do it
True.
and neither did the Reds, if you don't count their flesh mask.
I forgot about these guys! Why don't you count their flesh mask? According to Changes, some of them can use it to look like other people (one of them looked like Susan for the purpose of hiring a guy to kill Dresden).
If any of the Denarians can they've never done it in story.
True, but Skin Game shows us that Denarians don't have an anti-technology aura (otherwise Tessa would have triggered the anti-wizard defenses at Marcone's bank) so any Denarian that learns illusion magic would be able to use it as undetectably as a faerie.
I don't remember the name off hand but the were human who teaches the pack how to turn into wolf does.
Terra West.
The Hags do in the comic books and Dresden never tips to it until the end.
And last but not least the Ghouls can apparently pass.
I forgot about these guys too!