I would like to add a drive caddy in the 2nd DVD bay of my XPS 435MT. Before I buy the caddy, is there enough room to squeeze one into this bay? Is bay door removable? And, will the SATA drive I put in the caddy be hot swappable?
SATA is supposed to be hot swappable, but it depends if the power cabling is complete -- I wouldn't risk it personally.
If the caddy is designed to fit a standard PC case it should fit a DVD bay. Usually the plastic blanking plates on an unused bay remove quite easily -- on a Dell this usually involves removing the front fascia panel of the computer case first. The metal plate (usually) behind the plastic blanking plate for screening can usually be removed with a few twists so that the edges break where designed to.