How much "shake" at idle is acceptable?

I'd take a bottle of windex and individually spray each head pipe. They should all cook that windex off at the same rate. If one gets wet and then dries off, instead of sizzling it off right away, that cylinder is not pulling it's weight.

If it's bouncing header off the Torsion bar, that tends to make me think that the engine mounts aren't up to snuff.

And it's idling a bit too fast.