There's a thread about the poly counts here:
http://www.moreawesomethanyou.com/smf/index.php/topic,2216.0.htmlThere's really no easy, reliable was to mass scan objects for their counts that I am aware of, though you can check them one by one in SimPE. Honestly though, it's best to stick with getting you custom content from reliable sources who consistanly make their content with reasonable poly counts and preferably give the numbers out on their sites. Some people were good about doing that for a while, but a lot are starting to get lazy about it again. :p
Flamingo, I didn't realize that about the Maxis trash can. That's bad.
There's no excuse for it either, it's not that complex of a shape that they couldn't drastically reduce that number. I can though that I've never seen the Maxis stuff hit the 50k+ mark like I have with some custom stuff in the past.