If you're going to put ink on the quill I'd remove the cork from the ink bottle (if possible).. maybe have the cork dripping ink onto the table. Also, perhaps add a little more definition to the quill feathers.

I think magic is a fine reason for holding the gems in place, but if you want the added realism you could always wrap a tiny piece of steel-silk thread or the like around the gem that can be attached to the corresponding prong.

Overall it's just awesome... I'm so jealous..wish I could do stuff like that.