Good to see your posts, again. Regarding wire-up worries for the ECU, here's my thoughts:
- grounds good, between everything
- under-fuse every circuit while first testing
- time; not much of it without cranking the starter. Some systems are a little prone to sinking the injector drivers before cranking over, something to do with the first fuel shot for startup. If it doesn't fire right away, and stay running, cut the power to the ECU quickly.
- time (also); if the ECU side of an injector is shorted to +B (battery power) the driver (big transistor) will tolerate it for a little bit, but not continuous. It'll be dead on that hole.
- tip: if the exhaust sound is sharp and hard, it's rich; if it's soft and "mutters", it's lean. Always trust the tone of the sound to tell you the truth. You'll also feel the sharp "shake" on start-up of rich cylinders (such as leaky injectors). If you get banging and whine sounds from the starter, it's trying to start too far advanced or miss-wired ignition primary circuits.
Best of luck!
JimL