Does it break the theme when using mobiles, if I choose not to have “common icons” (speech bubbles) but only those larger ones that was added to 1.0.1?
I was thinking to make gray and colored icons and just replace those with the font-awesome ones to keep things cooler.

before doing this, it came to my mind that might that break something if using only 64x64 png icons on front of forum rows?

With mobile, forum icons, are hidden by default.
you can change the html in template to do that.