Found a few things on the HFA Songfile which I thought were interesting.
Victimless Crime, the song with Max Martin and Klas Ahlund, won't show up when searching for Kesha. I've never really known why.
Bonnie McKee also has a song called Hush Hush, which may be where the rumours of her being on Kesha's song of the same name stemmed from, but it has completely different writers.
There are two versions of Supernatural registered, interestingly enough one without Bonnie McKee as a cowriter. I think the non-Bonnie McKee version is actually some Piano Tribute to Star Trek.

What's even more interesting is that in the Artist/Album column for Supernatural, it has the following:
KE$HA COMPILATION
KE$HA DECONSTRUCTED
KE$HA WARRIOR
KE$HA WARRIOR (DELUXE VERSION)
KE$HA WARRIOR [DELUXE EDITION]
I'm really not sure what "Compilation" album Supernatural was on... any ideas?
Finally, Meet Me In Space, Young And Reckless and Not Obsessed are all registered, and all have the same writers. However, Meet Me In Space is the only one with "Kesha" in the artist column, and it's the only one we have a recording of. So I think it only lists Kesha's name in the artist section if she's recorded the song... which would suggest that MMIS and YAR are two different songs, not just a different title for the same song. Also Victimless Crime was most likely never recorded for this same reason.