It's a really interesting concept for a mod, I think.
The self damage only allows people to go for throws primarily, as oppose to going for damage, which is great
It can end up with some really nice counters and suplexes and stuff.
My main problem with it though is the gravity, probably just me sucking on high grav mods, but it just feels impossible to do anything because you're always being dragged down
The sumo 0 thing is fine too, people just can't grasp the concept of being careful where you flap your limbs.
IIRC original tk had sumo 0, and when Dargon and I put that setting onto the blackbelt room, we got an (or at least I got) and unholy amount of complaints.