Symmetry shouted: I might try. Never touched them when I was younger but could be fun
It has gotten WAY easier. EUD Editor 3 is kind of the standard these days, but I still recommend EUD Editor 2 as an entry point (it's still what I use). It's incredibly easy to do small stuff, and there's a nearly infinite ceiling for what you can do with clever enough EUDs. Kevin's idea is a good one, I think SkywinDragoon made a good tutorial on adding custom buttons in EE2.