Well with that last statement I have to ask. Backend wise, is your fe at least as good as gamelauncher? Because if it's not then this fe won't be particularly useful. I'm guessing it's windows only, so that's already one strike against it.
You say it'll work with any command line emulator. How? Will it support dat files? If not then the support really isn't that good.
I'm not trying to discourage you here, I'm just bringing up the point that graphically, this fe will be extremely limited. You'll have to make it very useful to make up for that, and gamelauncher has a pretty big set of shoes to fill. I know MANY people will disagree on this, but imo putting configuraiton options in the gui doesn't make it easier to configure. It's just a different way of doing it. Personally I'm too impatient for that and would rather type in settings manually in a good ole text file.
p.s.
About the transpartent gif border. Yeah a border as big as the screen in gif fromat, that won't slow down performance at all.