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.

Yes you do need a Architect and a Engineer. but you also need a contractor that can work with concrete to give you what you need. Precision-services.com has done this before. also check out this video chad@spidertie.com

Well it depends on your wall color as well . since you have such concrete looking floor I would recommend you can chose any electic color like lemon , orange , yellow to give a bright look and uplift room mood or chose any pastle color of your choice for subtle feel . :)

ips flooring tends to get a flat gret texture once laid and dry. How to get a perfect concrete texture on it? Like in the picture below.