I guess that the best questions are the following...

How flexible is the game "The Sims"?

Is there alot of public information out there (un/official) on hacking the
game proper? (not just objects) Software hooks? Plug-ins?
LINKS PLEASE!

Instead of pestering my friend...
(and his install of the Sims on his machine)
Should I:
a. Decide that "The Sims" is workable for my aims and buy it and all of
the expansion packs?
-OR-
b. Realize that I have to write my own simulator?