I think it's a great shade and it's actually lighter than you think! As long as you break up the lighting around the room, I think you should be fine. Personally I think dark wood features and accessories would look wonderful against the blue. Both the images below are examples of dix blue - one on the wall, one on the kitchen island!

A bench dining table would be economical in the space – you can tuck the benches away then? IKEA do a good, affordable range. Also, two smaller sofas or a couple of chairs and a three seater would probably look less imposing? You can get reasonably priced ones second hand or again even in ikea! Other than that, use mirrors to make the place lighter and bigger! :)

For me, it was a hard pick between the open plan kitchen and the staircase but if I had to go with one, I'd side with the kitchen. The deep teal and pale blue units pair beautifully and tie with the splashback, and vases. The added gold accents in handles, vase and tap adds some lovely metallic colour to the scheme which looks oh, so good with the teal. And finally, I love how the door frame co-ordinates with the light fitting and the socket on the island with the ovens. Superb, daring yet effective combinations!!!

Short answer... Yes Long answer... it depends