I think it sounds like a swell experiment, and I've been wondering about similar things.
The flood fill algorithm is an interesting question...
The other interesting question is: How do you do this safely?
And -- what improvements could be made to SL to both allow this sort of fun (oh, it's fun!) but still have safeguards... or at least retain some kind of control?
It would be nice, I think, if one could somehow get a report of EVERY object one owned anywhere in SL, and, ideally, be able to go visit and delete them.
I suppose one could write a drone which visited every sim and, with sensors, cataloged all the objects and generated a report... Of course, just one drone with a 96m sensor radius would take an awfully long time to do this...