Yep. Martin/DonQuixote's right.
And as for your second question, you'll need some basic XML knowledge to create a custom GUI. You can probably learn that online at W3C or something. Or alternatively you could just view the source code of the other 3 (or is it 4?) pre-made GUIs and figure out the stuff on your own, shouldn't be too hard (just guessing, haven't seen them myself

).
But then again, there's no real reason to want to make another custom GUI, I'm perfectly fine with the new layout
About the rating thingy, 9. Lost a point because you have to quit CCT before your times are saved

Once I was doing an average of 200 and my laptop crashed for some dumb reason at about #150 and I lost all my times. (Okay, this is definitely more my fault than CCT's, but...

) Just so that you know, clicking "New Session" doesn't mean that your current session is automatically saved (or all other previous sessions since you launched CCT for that matter), the only way to save your times is to close CCT (and re-launch it later).
So, if you just did an average of 500, then clicked "New Session" and left CCT open and went to feed your goldfish, and suddenly your laptop battery dies, or your goldfish trips over your computer's power cable (?), you'd still lose your session average.