Sure Occupy is less of a PO hit initially, but in the long run Raze is less.

Occupy -25 initially and -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 for a total hit of -80
Raze -50 initially and -5 -4 -3 -2 -1 for a total hit of -65

I can see the cost difference for converting some buildings, but if I have to completely dismantle a building to build something else in its place it'll cost the same as it would if I had just razed and not take the extra turn to dismantle before replacing. With Razing the city center and port are the only buildings the remain. All others are blank if the AI had built on them.