1. This one is simple, press F2 to toggle between face highlight/edge highlight. 2. I've actually never tried doing that, maybe someone else here may help.
Regarding this image, I have two questions: 1. More often than not, the polygon being selected within "Polygon Mode" isn't highlighted as red, as shown in this image. Is there a way to fix that so it shows up as highlighted? 2. How can I increase the size of the red edge lines being selected? I'm pretty sure I've done it…