Can a Scud missile be aimed and fired?

Not easily. For example, in the official OFP campaign mission "Search And Destroy", you cannot do anything at all with the scud launcher. It was originally meant to be an aesthetic prop and not much more.

However, there is a script that allows you to target the scud anywhere on a map and launch it. It has a "SCUD CAM" that lets you follow the scud down to its target. The explosion consists of a series of smaller explosions, something like a cluster bomb. Since it's a script, you're going to have to make a mission with it or find a mission that employs it.

You can download the script from the Editor's Depot section at the OFP Editing Center. It's under Script Snippets: Weapons & Ammo and is called "Scud Launch/Trajectory Scripts".