Hello Adams and Welcome to the Forum:
You seem to be most concerned about the floors, so we'll start there. The cut ends of the floor joists must be fully supported; if they don't occour over a beam or foundation partition wall then you will need to shore up a beam with concrete block piers. The piers can be placed on the dirt after leveling it out. See if you can get a come-along rigged to pull the loose ends together and, while holding them tight put a piece of 18 guage metal on both sides with lots of nails or screws in the metal plate. Each joist or at least every other joist should be rigged with the come-along. You will need someone on the top to let you know when the two sides are flush and you can use shims or wedges to even them up (before the metal).
As for the walls you could put a nice trim board over each opening.
The ceilings could use the same come-along operation; only to get a continous beam you will have to make it from the top. I would still use the metal on the splices, then screw a 2"X6" flat to the top of the joists and a 2"X8" screwed to the side of the 2"X6" making an L shape beam.
If the movement appears to be from settling foundations or if the ceiling has factory tursses in it we need to talk further. Let us know how it turns out, or if we can help any more.