A transformer will (or at least did back in GT5 official) output IC2-EU from a GT-EU input, might need IC2 cables to make it switch output but there's an easy config for that.
I tried a transformer. It didn't work. Unless maybe you mean an IC2 transformer? I was trying with a GT LV transformer.
What you can do with Heavy Fuel is to crack it, ideally with Hydrogen.
Right, it's an intermediate product. Since it had a name like "heavy fuel," I though it could be used somewhere as fuel.
I don't understand what you mean by a "diesel engine boosted by oxygen." Diesel generators only have a single fuel slot. The wiki says nothing about this. Are you saying you can pipe fuel and oxygen into a diesel generator?
I worked out the math for the Heavy Oil -> Cracked Heavy Fuel -> LPG transformation a while back. It's about 50% better than Heavy Oil -> Oil -> Nitro Diesel. I don't have an oil cracking unit yet, since my only source of oil up until now has been oilsand.
I don't have a distillation tower because it requires an EV pump, which requires titanium, and I don't have the vacuum freezer, kanthal blast furnace, or titanium chemical processing I need to produce titanium.