08 5.7 Starting issues

Hoping some of you can give me some insight on where to start with this. I just bought it with 149k in pretty good shape but now realizing issues with it where never addressed. Water pump leak, trans pan leak and rear main seal leak and a starting issue. I had toyota fix most of it this week other than their recommendation to replace the ECU transponder at $2500. In august the previous owner had toyota replace the parking brake sensor and cable as well. But it didnt solve the issue.

It only does it when its warmed up. Has full power but wont crank sometimes. If you put it in neutral it starts as well. Sometimes it starts and then stalls immediately. It also has a K&N intake as well. There is 2 amps and subwoofer under rear seat that toyota recommended removing to see if it solves the problem. Otherwise I need a ecu replacement they say. Not sure if I believe them. Where should i start? Sounds like these things are total piece of shit..

 

Fuel pump about to go out, possibly a immobilizer chip in the key failing.

 

They replaced the key already and didnt solve it and weird thing is that it will start in neutral too.