Hey.
Yeah, a lot of FPS multiplayer games feature spectating and it can be interesting and entertaining. I remember I spent some time on it in Call of Duty II ages ago to learn how to play..
But I don't think it is needed on our server. Default SAMP spectating interface doesn't feature first person view, GUI etc; besides, you can spoil players' tactic plans or see what you are not supposed to see while spectating - our game is not as dynamic as some FPS. As for tracking hackers... If you see one while playing, report him - either ingame or on forums, but you don't need to perform any additional actions about it.
On the other hand, I don't think it would really be 'abused' by players. Anyways, I don't see any good reason to add it, so
-1 for this suggestion.