It's been a while since ive played with a standard CA so some of this might not be 100% (Working from memory).

Most of it you can get rid of (won't be road legal though).
The one that goes just behind the throttle body is a dumb value (it is open when cold and uses a bimetal strip that when hot closes the value (Big cylinder that sits under the throttle body), it can be removed.
On the inside of the intake manifold is the Idle speed control value (I would keep this to get a smoother idle) and a Air conditioning idle up valve, its hard to separate the two so you might need to keep both. The air con obviously won't be triggered anyway.

At the back of the intake manifold is the butterfly control value and some of the original vacuum lines to control the turbo waste gate (If it remember correctly). You can disconnect the butterfly control as it is default to open, this may impact low/mid range torque. There are a heap of other lines back there that are for pollution control, which as said above could be removed but may render the setup not legal for road use. The ECU shouldn't care about most of this stuff.
There are some diagrams floating around the forum that details what the lines do (Search is your friend for these).