F/A Mix, Vacuum Pressure, Idle Speed issues

1983 Scamp GT

Idle has been rather rough, and stalled out at a stop a few times this past month. Looked for vacuum leaks, found two, and fixed them - at least temporarily. PCV hose is cracked at the air box, and can't find a replacement part. Taped up for now. Is there a hose by-the-foot that will work?

Tested manifold vacuum by removing and tapping into the hose in the front of the air cleaner box that says "to manifold vacuum". I think this is the right place? Coming up with 14-15 inches of mercury with a bit of wavering. Does anyone know the correct level this should be at? Having a hard time pulling up this info.

Trying to figure out what to do to check my idle speed because it feels low. Manual says to "Unplug the PCV valve from the engine and allow it to draw underhood air." Does this mean remove the whole cranckase breather element from the valve cover? Or just remove the PCV hose from the valve intself?
It also says to disconnect and plug the line to the CCEGR/CVSCC - I have a picture of what a CCEVS/CVSCC looks like and where it is located, but not a CCEGR. In fact this is the only time it is mentioned that I can find. Is this simply the EGR valve? Or would it be also known as an EGR Vacuum Delay or Ported Vacuum Switch? Scratching my head on these...

Next would be testing/adjusting the mixture. Vacuum leaks may have been the major source of lean conditions, but I would like to verify. What the hell do you guys use to turn those slotted mixture screws? there's like 1.5" x 0.5" clearance, no tool I own can make the cut.

Anyway, I bumped the idle up a bit by ear and it's smoothed out since the vacuum leaks have been sealed so I can at least get to work the next few days. I don't want to push it though. Any help and information is very much appreciated and welcomed

Thanks!