1) Batch fire is a fuel injector firing scheme. The injectors are fired together as a "batch". It doesn't care about specific cylinders. This is an older methodology than the modern sequential injection used by the B-Body (and newer cars), which fire each individual injector at specific times depending upon cam timing.
2) These videos are keeping the Optispark and using it solely to distribute the spark from the original single coil. They are bypassing the optical sensor and reluctor portion which was used to sense camshaft position.
3) The EFI Connection system completely removes the Optispark and replaces it with a 1X cam sprocket and sensor, and uses a 24X crank sensor. It uses individual coils for each plug. It basically turns the engine (electrically) into a LSx. It's not relevant to these videos.
This sort of setup could also be easily used on the '94-95 cars by swapping in a '96-97 timing cover, crank reluctor, and hub. The wires for the crank sensor would have to be added, too, of course.
Mike - '94 BBB SS (RIP 06/16) - '95 DGGM SS - '96 DCM SS - '92 BBB Wagon