OK
Picture 1 you have labelled correctly.
Picture 2 ? goes to the idle up solenoid you have asked about in picture 4 (with the green plug), specifically the end nipple, then the inner nipple line goes to the airbox on an AE86, or the I think to the intake tube on an AE82.
Picture 3: 4 & 5 are coolant feeds for the waxstat. 1 & 2 I think are for the power steering( block these off), 3 goes to the aircon idle up solenoid (picture 5, specifically the F [vacuum] outlet), the other outlet on this valve (e) goes to the airbox.
There is no point bothering with the two idle up valves in 4 & 5 unless you have the rest of a functioning idle up circuit. On an AE86 this is incorporated into the loom that includes the headlights and charge system from the fusebox in the engine bay around to the junction box in the drivers footwell, then across the car through various diodes within the dash loom to the ECU. Earlier 4AG AE86's then had an idle up computer (a black plastic box slightly larger than a ciggie packet) which clips on top of the ECU. I think later looms incorporated this within the ECU, and I think this was the case with AE82 twincams (?)
Your interpretation of what it does is correct. Having a functioning idle up circuit makes the car a lot nicer to drive in traffic. But you can get by without it.
7. You ditch the whole 4AC coil and replace it with a coil/ignitor setup from an AE82. Should plug into your AE82 4AG loom
8 you throw away assuming you have an internally regulated 4AG alternator. Otherwise you will need to adapt your 4AC alternator and keep this in the charge circuit.
