Pictures? Context is key.

Or a drawing at least! My head spins at reading your scenarios. 😊

Since common areas will be seen more often and bedroom doors are frequently closed scenario 2 seems like a good choice. A threshold can make a nice transition to bedrooms. Hallways work either way and will probably end up with runner(s) anyway.

There is no way to answer this with no context . A simple drawing showing the floor plan and the dierections you seem to be thinking of.

To avoid awkward hardwood transitions, you can lay the planks in a diagonal pattern or place a thin wood strip at the threshold of each room where the flooring changes direction. Hallways: Prevent a choppy look for hardwood flooring in hallways or narrow rooms by laying the planks outward from the doorway.

I tried to draw out a crude depiction of what I'm talking about. (Emphasis on crude...) to help visualize. Turn the picture on the side for orientation of the wood (i.e. as though you are entering thru the front door with family room on the left and the family room wood runs side to side; bedrooms up and down.) HOpe this doesn't end up adding more confusion...

Some people think that every single plank of wood in a house should be laid in the same direction and others like or are fine with a change in direction.

I changed the direction for the wood planks in some rooms/areas when we built the house. Photo shows a change in direction from a long hallway into the master bedroom suite. The MB suite has a hallway first and then opens into the bedroom. I preferred seeing long planks in the MB hallway and flowing into the MB.

Someone else might have kept it the same direction. Neither is right or wrong, just different design choices.