You can paint your basement walls any color that you like. Your entire house does not need to all be the same color. BORING!

I prefer satin for almost every surface because I like the little bit of sheen. It should help distract the eye from the vertical lines if you aren't going to fill them in (a lot of trouble for not much in results, IMO.)

Um... not all basements are dirty and dusty. Matte paint is beautiful but tricky. Benjamin Moore is SO flat, it's like chalk. so easily marked. I can't even clean it with a cloth without accidentally burnishing it. Never. Again. I have better luck with Behr Ultra. Their flat is more like a flat/satin hybrid. I've used it in several rooms now. Our basment was painted with Pewter Mug in flat, and even 2.5 years later, I still love it. would 100% recommend.

I assume you’re getting Samplize paint swatches or something similar to try in various parts of your kitchen and next to your floor and countertops. You’ve chosen cool gray colors do likely you’ll need a cool green, gray- green and will likely eliminate warm greens. For example, I like Billiard as a green for me because of how it’s a yellow - green and looks good with warm woods. But probably is not your green with that flooring. Some of the other greens are quite dark , kind of blackened, so see if they are too dark or instead give a good crisp look.