Testing of the EGR looks good, tested it at idle with a hand pump and the engine stumbled pretty hard. Also tested it with the engine running and revving up the RPMs and you can see the diaphragm operating. Did clear out the passages when I had it off though just to be sure.

Was also able to get the IAC off, cleaned it up a bit and put it back on. The o-ring was there.

Ran some seafoam through the intake and now I know how I can make a good smokescreen when necessary.

Tweaked the idle a bit using the adjustment screw and it seems to run much smoother when cold now.

Not sure what to look at next, set up an appointment next week to take it in to Greulichs and have them diagnose it.