Expansion is a big factor but you can think of the light of the CMB as having originated from everywhere. The part of the CMB we observe is a growing bubble. The light is traveling uninterrupted after having been emitted in the early universe.
To the second question, the expansion of space is not that significant between nearby galaxies.
socialister t1_j2ko2s5 wrote
Reply to comment by InSight89 in Is any "movement" visible in the fluctuations of the CMB over time, or does it appear static? by JarasM
Expansion is a big factor but you can think of the light of the CMB as having originated from everywhere. The part of the CMB we observe is a growing bubble. The light is traveling uninterrupted after having been emitted in the early universe.
To the second question, the expansion of space is not that significant between nearby galaxies.