When you have a large camshaft you have larger amounts of overlap. Overlap is when the intake valve and exhaust valve are open at the same time. This occurs with a big camshaft at the end of the exhaust stroke and beginning of the intake stroke.
At high RPMs the high velocity exhaust charge exiting through the exhaust port and pipes actually helps pull the fresh intake charge into the cylinder - scavenging. At the same time air velocity through the intake helps push the charge into the cylinder. With very large camshafts some of this charge is actually pulled straight through the cylinder and into the exhaust and wasted.
At lower RPMs there is not enough velocity in the exhaust or intake for scavenging to occur. At idle speeds the opposite of scavenging takes place - reversion. Hot exhaust gasses are forced back into the intake and the incoming intake charge is diluted making the engine idle rough.
Now this is my theory on why large intake ports can contribute to rougher idling . . . Larger runners = lower velocity through the port. Your new head's 195cc port is bigger than the stocker's 160cc. The larger port slows velocity through the port so the incoming charge has less "momentum" to push against those hot gasses trying to enter the intake so you wind up with more reversion and a rougher idle.
I'm not entirely sure why higher compression would hurt or help idle vacuum, but I believe more compression would create greater cylinder pressures - this I believe would tend to exaggerate what the cam is already doing. Better scavenging at high RPM and more reversion at lower RPM. Whenever I increased compression ratio in an engine, the engine always seemed to have a more distinctive "pop" tone in the exhaust at idle, but my theory could be wrong . . .
BTW - I wouldn't be too upset about your idle, I bet it idled pretty rough before the change anyway. Just turn the idle screw up a little and test it out. I bet you'll find you have a TON more power.
Also - you may be very close to needing the small holes drilled in your throttle blades. If you have your idle screw adjusted to high, the throttle blades get cracked open too far and the car starts idling on the main jets instead of the idle circuit.