Ok here's my test patch for the modes stuff.
It's tidy and the underlying code is well commented, but it's not UI slick or anything. I added some top level description on how to get started with it, but it's basically a single karma looper with lots of playback bells-and-whistles.
The descriptions for what each preset does is on the bottom right, and to use it, you just select the karma mode you want (top left) and then its specific preset (i.e. "dictaphone" or "sk-1" etc...), and after that you just use the karma looper as you would normally, and the modes stuff does the rest.
I'm especially pleased with all the glitch and tape modes, so if you (@dude) want to play around with this, have a go. It should be relatively trivial to strip out everything except the glitch mode and turn it into a TCG-flavored karma looper for M4L.