An Idea...

Most likely thought of plenty of times, but serioulsy to prevent most of this outstanding server lag and also overall lower the load time of clients and increase overall performance of SL in general why dont you just limit the amount of availible running scripts per parcel of region...

Prims are already limited and running scripts most likely cause just as much load time as prims or textures.

Think about it^^

Yeah and than limit the number of people who can visit your parcel according to it's size. And maybe put a little limit on how much chat can run at once at any specific parcel. I can think of tons of little "features" that will improve perfomance but will make your SL experience miserable. Terrible idea.
The prim limit is an economical limitation, so that people need more land to build nicer stuffs, not coz they hit performance. There are enough limitations as is in SL. If you dont like someone abusing the sims dont go to their casinos and dont buy land near them, and tell all your friends to do the same, think b4 you suggest "simple" solutions that will do more damage than good.