Very happy with this site, just wanted to toss out a few suggestions, mostly on the nitpicky side, simply because I want to see the site be all that it can be.
First, I think the RP Preferences could be expanded a bit. For my own purposes, the omission that sticks out the most is vore. I had no problem with giving some additional details in a few paragraphs under my "wills/won'ts", and I would encourage everyone to do that. But it would be nice for me to be able to tell at a glance if others had strong feelings for/against vore, because most people just select the dropdown items and leave it at that. I'm sure there's a few other kinks people might like to see added.
Another thing you might add to the preferences is a short menu for "mood" or "tone". Lighthearted, romantic, and dark, for example. Even something like rape can be played for laughs and worked into a lighthearted RP if it's done right (think of a situation in an ecchi comedy that doesn't shy away from its logical conclusion). This would help with knowing what type of RP you could approach someone with.
These next few things I'm not sure are possible, since I'm aware you only have so much control over the design elements of the site.
If possible, a person's Preferences should have more visibility, ideally being a full-fledged part of their profile. Currently I have to click a profile, click activity, and click preferences on the list on the left side in order to find out whether or not someone has filled out their preferences, and if they have, that's another click to reach that page. It would be great if it could just be rolled into the About Me tab or something.
It would be nice if the blurb that appears when hovering over user's names would include their gender and sexuality, and maybe the first few sentences of their About Me page. Currently the blurb really tells you nothing about the person.
I'd love a real friend list or address book easily accessible in the dashboard or home page. It would be great to have a readily accessible list of members who you like to RP with, maybe with the option of adding little notes to yourself about them (for example: "likes X" "prefers Y" "ask before trying Z").
Finally, I visit this site in a private browsing window. My cookies are wiped when I leave, so my color choice for the site theme is not saved. I've given up on selecting a color that I like and have resigned myself to the default purple. It would be awesome if this could be remembered by your profile instead of your browser.
Sorry to go on and on like that! It's only because I care. :)