Another vote for the MK pointy toe pumps. The color is the most flattering and the toe lengthens your legs amazingly. If they are comfy (and you are comfy with the budget issue) I say keep. The other K/R pair is nice, but not your skin tone and similar to the nubuck in toe shape.

Keep both patent nude shoes. (I am not certain which pair you meant was K/R). But BOTH have very distinct uses: pointy for white pants and jeans, and some pencils. Round for your more romantic flowey looks with dresses and some skirts.

Although if you MUST keep only one, then knowing your outfits and your style, I'd go with the rounded toes patent ones. Plus the fact that they are real leather means they won't let you down or hurt your feet in the long run (pun or no pun).

I like the MK slightly darker patent pumps much better than any of the other shoes. I feel like the shoes you already have are just slightly dated. The Bianco nude pumps seem too light. I know many people wear nude shoes in this style but I find it much more flattering when the nude is just slightly darker than your natural skin tone.

Don't have time to read everything right now, but just wanted to say that the pumps in #5 make your legs go on forever!