Pause function Update?

This may sound weird, but is there a way to pause the update function for a few seconds?

Use enabled = false, then re-enable it later. Of course, you won't be able to re-enable through Update() because Update() is one of the functions that doesn't run when the script is not "enabled". Like Eric said, coroutines are one way to re-enable. Here's an example of both of these concepts in action:

No. If you need to schedule events, use coroutines.