For the button font size, I looked at it with Firebug
, and it appears that the font size is set around line 662 of css/template.css with the following code:
I recommend installing the Vertex Upgrade Patch
as well, there is a whole new admin that should make it easier to find the settings you're looking for.
[Note: I am moving this topic to the correct board; please remember in the future to post theme/plugin specific questions to the board created specifically for the theme/plugin you are asking about.]