This is actually covered in the basic maya animation tutorial on motion path curves (well, changing and moving keys on the path). I can't remember what they say in there, mostly cause I mess with motion paths afterwards for manual animation, usually.
But if you look at the channel editor box for whatever you have attached to the motion path, there should be an attribute titled 'uValue'. by default, 0 is the start end of the path, and 1 is the end. Since you can key this value, its fairly simple to change the uvalue for a desired frame range to keep something from moving; do it the way anything can be keyed.
For panning around, I'd reccommend generating a locator that the camera is aim constrained to (so you can always know what its pointing at). I've never messed with zooms, but I assume it can be keyed in a similar fashion.