Some questions, some answers.
If you are pleased with how the original admin interface looks, you shouldn’t.
see Troubleshooting.
We are testing with Firefox, Chrome and Safari. IE9 and Opera should work fine as well.
Of course (better use markdown anyway).
For now, custom Compass-based stylesheets gives us much more options. But we do understand the need to easily customize the admin interface and we’re discussing this issue on a regular basis.
Occasionally, we discuss features and implementations.
Help is very much appreciated.
Our goal is that Grappelli will be redundant eventually (though we doubt that will happen).
Grappelli is developed and maintained by Patrick Kranzlmüller & Axel Swoboda of vonautomatisch.