Do any of you guys know if there is anything wrong with switching themes from one website to another? If you bought a theme and used it first on one site, is it possible to take it down and then use it on another site later?
If you're using a free theme, then you can normally use it anywhere.
If you bought it then it depends on the licence. Most licences allow you to use it on multiple sites or one site at a time, but some lock to a domain. Try contacting the person you bought it from and asking if it's not clear.