To summarize, Grace is a furry squirrel nudist who can shapeshift to all kinds of forms. Lets not forget about the random gender bending and other variety of transformation beams... including "Female Variant #5", which is essentially were-fanserviceism. Oh, and just for the mix, there's cat-boys and Hot Amazons, to boot. The crowning quote on the main page is there for a reason...
El Goonish Shive and other gender bender comics are typically fetish showcases, though in some cases that doesn't preclude them from being good and having interesting stories as well... still, it's a little hard to argue that EGS doesn't spring mostly out of Dan Shive's kinks.
ThisLampshade Hanging strip nails this troper's (and, undoubtedly, other's) experience with the strip to an eerie degree of accuracy. More on-topic, years of EGS exposure finally made her go "Weeeell, maaaaybe..." to Micro. Dan, you sweet talker.
Mind Control/Emotion Control: Chaos
Costume Play/Cross Play
This had a big Lampshade Hanging in an Omake strip, where Dan tries to play online RPGs, but he's forced to play a female because playing a guy would just confuse his fanbase even further.
Dan made a filler comic where he had a conversation with Ellen, only to miss half of it because he was distracted by "his fetish for women in suits."
Innocent Fanservice Girl: Mostly Grace, who would be a nudist except no one's told her what that means, also Amanda and other people under the effects of the furry-TF-gun.
Dan's mentioned on more than one occasion that he's split down the middle on what he finds acceptable and what he doesn't. See here (the "title") for one point-of-view, and here (Squirrelly Dan's comment in the final panel) for the opposite.