Ad/Poll/URL listing managment

most of your requests are possible with actual paid hacks, but if you intend to find free hacks, you may need to wait until someone build them for free, thing that i suppose will take a lot of time.

for the community events, vBulletin contain a good calendar with events manager... some hacks enable the admin to even add Event Attendants (users can identify if they will be present to the event) and some other features like that.

for the banner ads, i have myself some great hacks (non-free) that permit to have surrounding banners and specific sponsoring per forum-basis.

for the classified, i think that only photopost.com classified script is made to deal with vB itself... i used this software that may not be complete but at least answer most needs.

front page news is easy... we have some good portals here like the vbadvanced.com one that is completely built from vBulletin.

the poll script we have included in vB can be hacks minimally to add identification of votes (who voted what)... multiple votes are possibles too

a url lister (weblinks) script is also possible, there are some on the market...

good luck!