You can probably delete most of the vacuum except for the dist advance and C4 auto trans modulator line, brake booster, etc.
I still have all of them hooked up, including the Ported Vacuum Switches for the air pump, canister purge and distributor, as well as the air cleaner stuff.
Not sure it all works, but it's there.
I have the can purge lines hooked up, except the current carb does not have a vent fitting, so its blocked. The purge line to the carb and the purge valve and canister are still there.
The orig dist advance has two vac sources, from ported vac from the carb and from manifold vac. It runs on ported vac most of the time, but there is a little switch that makes sure its always getting a min amount of vac. There is also a PVS that puts intake vac on the dist to increase idle when hot.
You can remove all but the ported vac line and be fine.
I still have the vac line to the smog pump diverter valve, etc.
You need vacuum to the heater/ac controls, the cruise control, etc. There is a vacuum resevoir can unde one of the front fenders that serves these. Either keep it, and keep it functioning, or disconnect it completely, or you will have a mystery vac problem.