Wow! Sorry to hear of all the problems. However, you may have already passed the point of having tried TOO many things. Been there, done that. Whole problem "could" be only one single thing. But now, switching this with that, is just adding to the possibilities. My suggestion would be to put everything original back on, including the ignition switch, and start from scratch with the wiring diagram and a multi-meter. I found "noid" tester lights to check pulse from computer to coils and injectors.
I done forgot what year we're talking about, but the ole burnt wire in the ignition switch is possible on some older models. On and on into the darkness. Also I'd be careful of what you ground with jumpers. The ECU is VERY expensive.