The first one might be to your oil pressure switch. If it is then grounding it will light the oil bulb. If not, that would be a bad idea (blow a fuse). Check a wiring diagram for your year. You can find many on FABO. The switch is behind the distributor, so looks like to fit you must run the harness behind there.
The 2nd photo, grn wire looks like a broken wire, maybe to the horn. Since the insulation is cracked, you should slip insulation over it (maybe heat shrink) before you reterminate it. I don't know what the booted connector in the air is, but many water temp sensors use those.
3rd photo, I don't see the question. Looks like a pressure sensor on the AC that is probably part of the compressor clutch circuit.
