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.

Here are some photos that may help you. You have the ceiling height to have a nice heavy rod just above the top of you window that could run the ceiling width. That will give you the space to draw curtains back to expose the entire window. I highly suggest that you work with a designer. A good designer has access to literally thousands of fabric choices and will be able to help you in selecting the perfect fabric and design for your room.

Susan, I find that people often make their coffee tables too low and too small. Measure the height of your sofa cushion and pick a coffee table that is a similar height. Also, in the layout you posted above the room would look better with a larger coffee table. Even as long as your sofa, or close to it. Let me know if you need one custom built, it easier to get the right thing for your room than you may think. Here is my etsy store if you end up needing one custom built. www.etsy.com/shop/MetalTreeFurniture

I feel partitions are not needed. You already have too much for the space. Adding a partition will shrink the space further. The simplistic solution, you do not wish to discard any furniture would be to paint all the walls in lighter pastles. And use some wall painting frames to highlight certain walls.