I had storage under my stairs in our previous home and am having it done again. I loved it. I put seasonal things such as candles, wreaths etc., that I could not put in the attic in there. I had considered making shelves/built-ins in the hallway under the stairs but I decided I would rather just have storage. It is also a great place to store the vacuum cleaner. Mine is open all the way under the stairs, the framer was going to wall it off and make it like a coat closet but I felt like that was wasting space. IMO it's great.

A houzz contributor, not too long ago, had made a wine rack out of 4'x4' wooden pallets, that are used in the US to move a load of goods with a fork-lift truck. Perhaps they have them in your country. He cut them in half so they were only two feet deep and stacked them up to high counter height. The wood would be a nice contrast with your concrete, might add a little warmth to the space. cascio.offsite@gmail.com

I think a comfortable distance between the island and the counter is around 42". It seems that you have only 30" between your cook top and the counter. I might be a little too tight. The wall between the entrance and the kitchen could be 4' long instead of 6', you would then be able to move the island a foot which would give you more room between the cook top and the island. Could you switch the location of the toilet and vanity in your dad's bathroom so your enter facing a vanity instead of a toilet which is a lot nicer.

Rules can be tricky, because it really depends on the chandelier, for example, does it have a small metal part in the middle or any crystal pieces which hang lower than the majority of the chandelier? We like to be able to see underneath the main part of the light fixture, when standing beside the table - if for example you were using the dining table to serve buffet style... or for a wine tasting. It's best not to cut too much of the electric wire or chain until you're sure you like the length. I hope that helps?