Is it possible to sell all your buildings in a city you know is going to be captured?

How do i know what buildings per era will show up in a newly settled city? i am weighing the options of razing and placing a new city to that of taking a city of an enemy.

Buildings cannot ever be sold in Civ 4. Newly settled cities never have buildings. The only time you'd get a building in a newly settled city is if you have a wonder which provides buildings in all your cities (like monuments from stonehenge).

Newly settled cities never have buildings.

Not quite True,

The only way to truly get newly settled cities buildings is from the advanced start option. However you cannot engage in combat with this option, so any discussion about razing is senseless.

Not quite True,

The only way to truly get newly settled cities buildings is from the advanced start option. However you cannot engage in combat with this option, so any discussion about razing is senseless.

I think I misuderstood you, but you certainly can engage in combat with the advance start option.