wiring issues, does this make any sense.

Disconnecting the battery with the engine running is a bad idea. The electrical surge can damage the computer and other electrical equipment.

Grounds are important to any electrical system, and especially to computers.

1.) The main power ground is from engine block to battery: it is the power ground for the starter & alternator.

2.) The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges. Any car that has a 3G alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects.

3.) The computer has its own dedicated power ground that comes off the ground pigtail on the battery ground wire. Due to it's proximity to the battery, it may become corroded by acid fumes from the battery. It is a black cylinder about 2 1/2" long by 1" diameter with a black/lt green wire.

4.) All the sensors have a common separate ground. This includes the TPS, ACT, EGR, BAP, & ECT. It is a black/white wire connected to pin 46 on the computer.

5.) The O2 sensor heaters have their own ground (HEGO ground) coming from the computer. This is different and separate from the O2 sensor ground. It is in the fuel injector wiring harness and comes out under the throttle body. It gets connected to a manifold or head bolt.

6.) The TFI module has 2 grounds: one for the foil shield around the wires and another for the module itself.

7.) The computer takes the shield ground for the TFI module and runs it from pin 20 to the chassis near the computer.

8.) The computer's main power ground (the one that comes from the battery ground wire) uses pins 40 & 60 for all the things it controls internally.

See http://www.fluke.com/application_notes/automotive/circuit.asp?AGID=1&SID=103#volt for help troubleshooting voltage drops across grounds

Probably, it loses its ground when the negative cable is disconnected on the battery.

Should it die? Yes: it may run for a few seconds, but it will die.

The alternator uses the battery to provide the power for the field windings. No battery, no power for the alternnator field windings. No power for the field windings means no output for the alternator. No alternator output means no power for the computer, fuel pump or ignition.