Information on changing fonts is at:
Edit: This is for the font face, not font size. Still need the other changes outlined above for sizing.
I play on a TV and I've settled on Source Sans Pro from the Google Fonts. It is available under the Open Font License.
I just found the link with the full details on substituting fonts so haven't played with all the options yet. I used SourceSansPro-Bold.ttf for m