You won't regret trying out the graphic mods, lol, it's a world of difference when you need to tap out 16ths of a beat that are close together.
As for programming, I have no clue how to do this kind of stuff, I'm a web programmer, if you could even call it that (HTML/CSS/XHML/PHP). I just happened to browse the application folder one day and realized the game's resource files weren't locked away inside a binary file. I just dragged them onto my desktop, made some tweaks and everything worked
Lastly, I too have noticed some seriously problems with some of the itunes songs out there. Quite a few seem unnecessarily difficult with successions of taps on all 3 chords. That's not fun people, fun is patterns that have your fingers dancing on your screen and then challenge your muscle memory by changing the patterns and forcing them to do something different. There's a song that you can download titled Grey Does Matter - Already. I'm not too keen on the song, but it has a great tap sequence and it works well for the game.