Wow! Super lucky to have the luxury of extra space! I can't tell you what to do exactly with your space, but I would suggest to change out your garage door. I love this idea, and I would really like to utilize it when I build! If I can't have it...I'll just be happy that someone else is enjoying it in the meantime!

I like second plan! That space will fit the wardrobe perfectly. Take all colors from the art. The colors can be lighter or darker than the colors you see in art. Take "Venice" with you to paint store and they might be able to help you choose good colors. Idea: paint four walls the same and see if you like that. If you feel the room lacks interest, then paint the accent wall. Choose a pale green that harmonizes with "Venice" and a darker green accent. Yellow + red accent White + blue accent

am assuming this is a concrete structure, when shifting service toilet to utility area, and if there are apartments above, then running extra lengths of supply/drainage lines & introducing a structural sink slab (if this is concrete) under the new location can be charged extra.. it will be easier to divide the 3rd toilet. all services will be already available. only, do check on supply & drain pipes capacity as load is increased on the same pipes which were serving one toilet earlier..

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.