Great space. I would consider swapping the curtains in the kitchen for a blind, the mirror in the dining area for wall baskets and the light fitting for a more understated one

i think it's nice to have some statement chairs around a table

I also prefer the table aux naturale, but if you want to paint it use an Eggshell paint (oil is tougher than water based), it gives a soft sheen. So as already suggested lightly sand to key the paint, then a couple of coats of primer, then a couple of coats of eggshell. Make sure each coat is thoroughly dry before applying the next one or the finish will be tacky. I personally detest chalk paint. I used it once on a wardrobe and it was very dry and difficult to brush. It’s marketed as easy, but it isn’t and it still needs waxing or varnishing to finish. Someone has made a lot of money selling that paint! I painted two bookcases in Little Greene eggshell and I’m very pleased them.

If you moved the proposed storage built in to the wall between the lounge and the dining room it would keep the room square allowing for the table and chairs to be aligned in both directions. Would work particularly well with a circular table. Also you could have floor to ceiling cupboards with glass doors at the top and solid at the bottom to hide the less lovely items. Narrow cupboards at 30 - 40 cm depth with lights could work well.