To customize your avatar just use the inventory tab on the messenger.
You can change what your avatar wears with that. Its very easy.
If you want more stuff to wear all you need to do is purchase it from the catalog.
http://www.imvu.com/shopYou'll find furry ears, tails, wings, etc. in the accessories.
The female catalog is more organized and has a larger selection than the male one does.
To perform actions and such all you do is click on an avatar and select what you want to do from the little menu that pops up.
The rule regarding not saying bored was most likely set in place because it's very annoying when you have a bunch of teens
saying it all the time. Plus it does have a negative effect on conversations and stuff.