I've made the offer to allow them to include several of my Serene styles with the default set.
As for templates; we don't really have the ability for admin's to allow separate templates to be selected; I'm hoping this will come in the future as it'd allow for so much more (look how drastically a theme can change in say PostNuke with different themes....
There are several designers (such as myself) who create themes that you may want to give a try though; I can't vouch for rates of others however.
I'm not sure if things will actually *change* with threads until we allow different template sets; as "hacking" your board kind of voids ones ability to seek support from Groupee's helpdesk, and modifying a template counts as hacking the board...