1.) your username IS bold, if you want it like mine or Trey B.'s, with the outline around it, it will make it even bolder than it is now along with the outline. If that's what you want click the option called "Shadow Color For Username"
2.) I have the same problem as you with the "Change Color" option. You have to type in the color you want which is dumb to begin with cuz how do I know the computer's stored colors have the same name as the color I want. I've tried putting color names like Yellow-Green in but it didn't work so I then tried a simple color like Red and still nothing happened. IMO there should be a pallette there to click the color you want rather than typing it in. I've blown thousands of points trying to figure this option out and the only color I have gotten to work was blue for some reason.