to make a camera pan slowly to a different camera, use the action "Apply camera object (timed)"
Apply the camera you want, and then the time u want it to take to pan.
Then make a wait equal to the camera change (unless you want things to happen during the change).
If you want to do a series of camera changes, one after the after, all linking (i.e: winding through a forest) then you'll want to make the wait about 0.50 seconds shorter than the camera pan.
Other things will be easier for you to understand if you experiment. Open a new, small map, add a couple of things, and experiment with the camera actions....
Hope I helped....
Cam