Something else you can do, especially if you only need one skill bar:
Take your second skill bar, set it to 2x2 grid, lower/raise transparencies and borders to your liking, then drag that to the center of your screen.
I see that you can't quite understand that 'just making a dot' isn't as easy as you think it is; If some one 'just made a dot' and kept the standard UI, you wouldn't be able to click on anything on a quarter of your screen because the skin would take up that much extra space even though it is transparent.
So, I leave this here, but it may be against the game's TOS/EULA/whatever legalese. Also, it is highly likely to be some form of malware.
Your mileage may vary with that program. I tried it and it would not respond to the keyboard shortcuts, or it would randomly start blinking and changing size. But it worked ok on a different computer.