Could you move around with your joystick using CME commands?
No, that doesn't work for me.
I just verified its not enabled, so wondering if you are confusing fixed view where you just sit at the center of the field, can rotate but not move.
What we are talking about is indeed "Fixed View Mode" (as called per key mapper), by default F5.
With F5, followed by F8, we used to rotate and pan around a point centered on the base we are on (or plane, if on ground or if bomber, in the air). While doing that, view was always centered on that point. Of course that could be used to look for vehicles directly on base, but as you technically were still in tower, you couldn't use range vox or room text to relay that info.
It was more convenient to spot for a CV nearby. But for a B-29 flyer it's an extremely important tool to find a place to lift off from, especially for new maps, even more since AH III with it's more obstructed airfields.
Now all it does is planting your nose on the grass in the center of the base.