They also represented the soldiers broken by war. Unfortunately, because of the kind of culture and imagery Tolkein (who was an anti-fascist and almost certainly no more racist than the typical right guy) was surrounded by, they also ended up as a stand-in for the Yellow Peril.

And no, we don’t see what the orcs become after Sauron is defeated. They’re kind of forgotten. Rich realm for fanfic! (Or even profic if you can successfully file off the serial numbers).

I’d say that the orcs would be very confused for a while without anyone to tell them what to do and likely whatever society they build afterwards will start out very hierarchical and rules-flavored. You might want to look at blogs written by people who had to grow up under *extremely* authoritarian parents.