Your current buttons are about the minimum size I'd recommend on the 3000. I've had a terrible habit of making my buttons too small sometimes. A good rule of thumb is to make sure that no button is shorter or narrower than 50 pixels. Even that can become a little cramped if you put a lot of buttons on the page.
Nice looking design, by the way.
I'm a member of the Remote Central community, just like you! My comments here are my own, and in no way express the opinions, policies, or plans of Universal Remote Control, Inc.