We recently did what you're describing with the black ceiling paint (pro tip: don't use strictly flat black, pick a shade of black which has some of the wall colour in it). Our walls have the tiniest bit of green and blue in it, though it's predominantly grey. The slightly lighter shade of black with a touch of green makes the ceiling disappear as has been noted, but the way the light reflects off the walls makes it feel "warmer" and the black paint doesn't seem as dirty/dusty. I also have low ceilings so this was key.

Absolutely absolutely absolutely have a contractor do the painting and make sure they use contractor grade paint (e.g. Sherwin Williams 200 or 400), it is significantly better wearing and thicker than crap from lowes or HD. Sherwin Williams will not sell their high end paints to regular customer, so you need someone with an account there.

We laid down vinyl plank flooring with an underlayment and man is that better than concrete or tile! Softer quieter and still looks good (until it got hella scratched taking my old TAF out of there...)

FWIW I also built a little platform I could put between the last step and the wall, effectively raising it to the level of the 2nd step which lets us pivot and rotate a pin without scratching the hell out of the floor or steps. It gives us a wider base for turns (can get a wide body up and down with no issue) and one less step to go up and down with the dolly!