Not to mention all the info he asked for is already right there, readily available if one would just read the post. But that's the way things are going around here, cookie cutter responses with very little "help" from some.
For the reverse lights it can be a ground, but if it was, then you'd likely have a problem with the brake lights and park lights as well, as they're all using the same ground. So this makes the switch on the side of the transmission suspect as well as the fuse that feeds it (Turn/BU fuse #16 in the dash), but if your turn signals work, the fuse is ruled out.
The dome lights ... Could be a grounding issue. Power is supplied by the Ctsy fuse, ground is provided when you open a door or override the dome lights on... So there's a missing connection somewhere. Could be as simple as tightening the two screws holding the dome light housing to the ceiling, as the map lights SHOULD be grounded via a ring terminal around one of the screws.