I know what you mean about the cinder block. That certainly will work but the painter really needs someone standing at the ladder base as a precaution. Also, depending on the stairway height and width, obtaining the necessary angle for a ladder may not be possible. Check your local rental center. Small scaffoldings with adjustable legs are made for working on stairs. You'll have a larger working area. The rental rates generally aren't unreasonable - maybe $100 per week. Hope that give some encouragement.

Something that I did is to sponge paint or texture sponge my transition color over the top of bottom half of wall-just make a line following your steps about 30-36" down nice and straight- use frog tape to make it perfect-then continue with your second color to rest of the basement. also keeps finger prints and marks to a minimum as the folks and children who use the stairway will not be noticeable. Don't have to have a fit when they touch the wall (!) Folks in general don't seem to love sponge painting idea anymore but I get compliments all the time on my transition paint job in the stairwell. Good-luck to you with whatever solution you choose!

I don't know why with handrails there would be anything against code in this stairwell, the landings seem long enough top and bottom and in residential there's no need to break flights like this with an interim landing. If you had a high budget you could do mural wallcovering on the right side, so you see it from the door. I would probably do a nice finish on the stairs with a fitted runner up the middle in a patterned carpet, a nice handrail, and a chandelier over the middle doorway and a smaller fixture on each landing all in a purely symmetrical way. I would also probably light the windows from the outside so light was cast into the stairwell from the outside as well.

It's not really just nail pops. You can see drywall lines, flaws, past areas that have been patched. None of the other walls are this bad. Not sure why the stairwell looks the way it does. That's why I was pondering whether a darker color would hide some more than the current color or even a lighter color. I tried to repair a lot before the painters came in last time. Now we have really expensive carpet on the stairs so I don't want to do a lot of repair work and risk getting anything on my carpet.