Hi,
I've been using Linux as my main OS for nearly a year now. IMVU has "just worked" for me in wine 1.5+. Recently I switched to Arch Linux and everything has been great! I have Wine version 1.7.22 at this time of this post, but whatever happens to be the latest in the Arch Official Repos. I also use the latest non-beta version of the IMVU client. To make things run a bit smoother I had to add
<option name="force_s3tc_enable" value="true" />
to my user's ~/.drirc config with a Intel HD Graphics card, maybe different for others but it worked for me. This is all on a Acer C710 Chromebook which I preformed the bios mod which allows me to install and load a full OS over the watered down Chrome OS. I have had success in the past running IMVU on a different laptop as well.
IMVU preforms pretty well but you must make sure you have OpenGL set or it may crash. IMVU only freezes a split second when someone joins or leaves or changes outfits, the pause is so brief I don't even mind. Also it seems if you preform the "special" right click menu any options found inside that menu will insta-crash IMVU so avoid that. The "avatar menu" you get when you click a avatar does work as well as all other features. Just that one I mentioned is all I found so far that will crash IMVU assuming you've set OpenGL.