If it leaks good, I wouldn't worry about the rings too much. I have a hard time believing it could wipe out the 2nd ring for oil control, but not the top rings for sealing. But if someone has seen that before, it'd would be an education for me.

When you say it won't work on the E85, what exactly is it doing. If it's running rich, you mean the wideband is showing rich, or you have some other perception of it being rich?

I'm not super familiar with the FiTech, but most EFI systems when the wideband is a ton off, will self correct. If you're not seeing it correct the AFR, then my guess is there is some sort of setting in the FiTech that's preventing it from doing so.

When you switch from gas to E85, what settings are you changing in the FiTech?