Nothing like mocking up with real stuff! Looks like you can make it work. Remember, the items will be back from the wall a bit if you have open plumbing. For purpose built darkrooms, drop tables are nice, as said, so you can have the enlarger up higher like 32 inches or even 36 inches rather than the 26 inches which is common table height. If you mount it too high you can always build a low 3 inch box to stand on if you need to. I built a workbench high, the height of which I found by the best combination for close work leaned over only very slightly plus my natural bend of arms while planing. I'm very glad I did.
Re paint: I'd suggest light bright spectrally neutral gray all over, but 4 feet and 2 feet of matte black in the enlarger corner. Reduces splash of light while burning and dodging.