I'm Devo Stevo new to CF. My daily driver has been no start for 2 months. 2000 2wd (Astro) GMC Safari van 4.3 L stopped running on a 3 lane highway and coasted into a gas station. It's had a common Astro/Safari history of not starting in heavy rain and hurricanes but that issue was resolved 3-4 yrs ago at a garage that did a tune-up, cap, rotor, plugs, wires. I thought it was the same problem again so I did a tune up and realized it had jumped timing so I changed the stretched out timing chain and sprockets, CKP sensor, and oil pump since the pan was off.

The main problem is there's no spark at the plugs, but there is spark coming from the coil. I'm not a pro so that makes no sense to me.
Clue: ground short? When cranking engine the Fuel gauge loses power and goes to empty, let off the key and it goes back to accurate reading.

Also no 5v signal at camshaft pos sensor or crankshaft pos. sens. During one voltage test of the cmp I found 11.8v on the signal return. but now it's 150mv. There is a 5v ref at the MAF, and EGR and I'm getting com with OBD11 so I assume the VCM is not fried.
DTC's:
P0452 EVAP pressure sensor/switch circuit low,
P0463 fuel level sensor "A" circuit high,
P0713 transmission fluid temp sens "A" circuit high
P1122 Throttle pos. circuit signal intermittent low
P0122 throttle/pedal pos sensor/switch "A" circuit low
U1016 History lost comm with engine control system
U1016 History airbag lost comm with engine control system

According to the wiring diagram a lot of this stuff shares a ground wire and a power wire. I'm brand new to this only studying Scanner Danner for a couple weeks so I'm a bit overwhelmed.

TIA, for any advice you can give.