If you can't stain the maple floors, why are doing anything to the floors besides just doing a polish to address any scratches?

leave the wood posts on the railing as is.

Leave te railing as is staining it will be abig job as all the finish on there now will have to be removed then all snaded to barewood before staining seems like a big job for no purpose . I see nice looking flooring so not sure the reason for the refinish , Maple yellows with age some finishes can slow that down but not stop it. MY opinion inless the floors are in bad shape leave them save the money for something else .

Wait until your floor job is done. The railing and bannister are fine. If you think you hate it, cover it with black fabric for a week to really get a sense of what black will look like.

I think it will seem very harsh once your floors are redone and shining new. Your house is soft colored, and a black railing will look strange.

If you stain the stair railing, what will you do with the stair treads? Stain them as well?

Our floors are very scratched from the big dogs we had previously. You can't see this in the pictures. I also hate the orangish-yellow coloring. The contractors said that 3 coats of waterbased finish will help eliminate future yellowing and oil-based finish would cause it to yellow again. Has anyone seen stained maple that turned out well?

I also agree to leave your stair railngs “as is”. Nice home!!

I would leave the railings as is, even though they may end up darker than the new floor color. They will still blend. You could consider painting just the vertical portions of the five newel posts black to go with the iron spindles.