1997 Pontiac Transport Montana 3.4L

This story is a long saga but I think it would help to have all the information.

The van has had intermittent problems for about 5 months, shifting weird and losing power, never giving a single code from the begining to the end of the story. Before anything was done it would run exellent for about 3 minutes in the morning, then it would bog like there was no power. I had to floor it to keep up with traffice off of the light. It would hardly accelerate and struggled to keep a constant speed of 35. I replaced the plug wires and ignition module with no effect. I then took it to a shop because I was at a loss. They said the catalytic converter was plugged. So I took it home and did that job. You could see through the honeycomb in the old one but I swapped them out anyway. No change. I took it back to the shop and mentioned the shifting issues and asked if the transmission could be at fault. They kept it another day and said the next day that they believed it was the tranny. Since this is the wife's car I took it immediately to a tranny shop and told the story. They kept it overnight and drove it and said it was definitely toast. I told them to rebuild it and they did. I go to pick it up and it drives the same... So I then started looking at the van again. I noticed that the camshaft position sensor retainer bolt had fallen out and that the plastic flange around it had completely broken off. I had a thought that perhaps it was inching out of the hole and only worked when cold because of no thermalexpansion (seemed plausible at the time). I used a bar of metal to try to tap it slightly back into the hole. It didn't appear to move but I gave starting it a try. It wouldn't start after this. So I thought, yippee I found it. I disassembled it. While disassembling I recalled reading that some systems have a magnet on the camshaft. So I rotated the motor by hand and noticed there was no magnet. I panicked and read on the internet that this was not the case on this motor and that there would just be a gap in the ring on the cam, (relief). So I reassembled everything. Then tried starting it. While doing this it appeared that it wanted to start so I kept trying. I made sounds like it had fired during an exhaust stroke and burped out the exhaust a few times. Then it fired, what must have been, way before TDC and everything slowed and made a horrendous sound from the starter. I think it rotated in reverse causing a huge amount of torque in the starter because the nose broke off of it. So now I've replaced the starter and I've also replaced the crankshaft position sensor under the crank pulley too. Still no start... It seems to behave the same way as it did after I replaced the camshaft sensor. There has been a few pops and a few instant stops and then the starter manages to get going again. I have stopped fiddling with it for now. I have worked on and fixed plenty of cars before but this one has me stumped and approaching broke. Any help would be massively appreciated, Thank you!

Country: United States
Make: Pontiac
Model: Trans Sport Montana
Year: 1997
Engine: 3.4L

Already Tried:
Ignition Module Ignition Wires Camshaft Position Sensor Crankshaft Position Sensor Starter