How old are you? Do you ever go up and down those steps with things in your hands/arms like a laundry basket, or coffee mug?

40 and rarely use the rail. Hardly carry things except for laundry or bags of clothes.

Per code, it is probably required. Remove if you want, keep it to replace when moving.

Leave it and paint it. It probably keeps you from bashing into that extra pointy molding above it. :)

You need the railing. I would paint it if you don't like the stained wood.