if a unit has the hover move type and it is being held in a cruising VTOL, and the VTOL is salvaged, can the cargo be dropped, or does that only work for Jump Jets special equipment?

im not sure a salvaged transport can drop its cargo at all...

No the vehicle carried in the cruising vtol would be destroyed since it can not disembark. A salvaged transport does drop its cargo, as long as it can legaly disembark.