NOW you want to confuse us with simplicity! If you have a problem both starting and running it's source is the likely the same problem. You've got to remember in starting mode the EGR is mechanically locked out (with the thermal valve) and the O2 is locked out by the
temp sending unit via the ECM so you eliminated (providing you've followed previous advice) the EGR, the temp sending unit, the O2 sensor. You're pretty sure you've eliminated all potential vacuum leaks
(although that plastic tubing can crack and not show it and there's nothing obvious like a big hole in the air intake. So maybe it's electrical.
Two things: 1)Check the control relay and fuse clip for the fuel pump.
Check the fuel pump wires. More than one of us (me included) has discovered bad connectors back at the fuel tank or corrosion in a connection point. Relays are cheap so switching one out to eliminate a faulty one is not a big expense. The relay is supposed to feed off the battery at start then switch over to the alternator power to run. If you're dying within seconds of start it could be a relay problem or the alternator. There are posts that point out why most shops don't pick up an alternator problem on these engines... they're special 2) If your MAF was replaced maybe pop the connector and give it a shot of electrical contact cleaner and blow out the venturi with air. While you're at it pull the connector on the alternator and give it a shot of the cleaner too. Check grounds. All the electrical depends on good grounds and there's a bunch of them; on the block, on the valve cover, on the intake manifold. It's something simple. It's a process of elimination.

And another thing: if the thermal air by-pass valve on top of your thermostat body is opening you are running too hot. That's supposed to be the Hail Mary rescue to cut down the engine temp by bringing in cooler air directly to the throttle chamber. That opens at 180. Normal engine temp should be 160. I drove around for a long time thinking the temp guage at the halfway point was great and wondered why my feet would bake while driving in the summer. Changed the stat the pointer went to 1/4, the engine ran better and my feet stopped cooking.