What spotlight beam angle to choose?
How long should a rope be?

There is no right answer, it all depends on what you want, and how much space you are lighting. Generally speaking, spot lights will create a more dramatic scene, while floods create a relaxed casual feel or uniformly bright work area, depending on intensity.

if the fixtures pivot/tilt somewhat, spotlights can be used towards a wall to highlight a piece of art or family photograph. A lot of people still like straight-down spotlights in the hall, it tends to make space look bigger, and uniform lighting is not important in an area you don't stay in. Floods in the hall will work just fine, you just won't have the six bright spots on the flooring as you look down the hall.

In the bedrooms, you probably want those to be floods to create a smooth uniform calming light. However, you don't have to be homogeneous, especially if you have 6 fixtures. You can put out a lot of light with 6 LED bulbs. One of those can be a smaller angle to create a (slightly) more intense light on a desk, reading chair, or decoration.

TLDR: use 120s except for effect.