Wonder what happens if you lose the race for a wonder, capture the city where it built and raze it. Would you get to continue where you left off?
I'm pretty sure that the way it's implemented you can't actually get the free Policy Slot more than once. Not that the effort would be worth it anyway.Coupled with the fact that policy slots count as one-time bonuses that aren't removed if you lose the wonder, this could be abused to get unlimited policy slots. Conquer a city-state, build, say, the Forbidden City there, have a friend take and liberate it, repeat unlimited times.
I think razing cities should keep the wonders. They can be like a natural wonder where you can settle near them in the future.