2) As a bit of history - most of the themes on the site currently were designed / build by students as part of the GHOP program in 2008 it must have been. Not sure how many of those guys are still lurking round to offer support. Most I believe haven't stuck around. I haven't had to deal with any authors since the initial build and review so support I'm not sure.
3) As for features lacking, one of my *big* issues with the theme support is that you aren't able to easily bundle PHP code with themes so its very hard to bundle homepage layouts or specific widgets or anything else (like a custom login form). What I would like to see is the idea of 'sites' rather than themes as such. So a theme (or rather a created 'site') comes with a theme and its own set of PHP code for a customized setup.
But changing the current system is going to open up a whole nothing discussion :)
Thanks for the responses! Will, it sounds like you're envisioning a theme framework of sorts, which is what I was using with WordPress and Thematic before making the move to Silverstripe. I think it'd be a great idea to explore further with Silverstripe...
I'm not much of a back-end developer, so I figure this is the best way I can give back to the SS community. My idea is to create a nice bare-bones, modular grid-based structure that comes bundled with a handful of different skins. Once there's a solid framework underneath, extending that in different ways becomes a breeze. I'm also contemplating including some light JS scripts to provide basic functionality like animated scrolling (back to top buttons), tooltips, etc.
The more ideas I can get from the community the better, and if anyone would like to volunteer to review in-progress work just let me know :)