I have a 99 caravan and when i took off the brake pads, the rotor came off in my hands. Is there anything else suposed to be holding the rotor on?

Also my rear hatch lock is stuck in the locked position, is there anything I can do to disengage the electric lock?

Nope, the caliper and the lug nuts hold the rotor on. I don't know about your hatch, sorry.