How is your house affected by outside noise? I was thinking of a staggered stud outside wall construction, also saves on heating or cooling with extra insulation, and consider what is called an air tight drywall method to control air infiltration or out, eating up heating/cooling costs.
If nothing else, do this for the theater to cut sound leakage with extra door seals as on an exterior door.
This is what I did with my house that took 3 years to build by myself.
Also, trace your habits of living, coming home from work, retiring at night to set up light switching patterns unless you build smart home and voice activated.
Landscape lighting? if so, think where the low volt transformer goes and how many you may need.
Think about that tub as well. We never used it, waste of $ and space. Make the shower large as possible so your elbows don't hit anything; you should be comfortable, you are custom building here.
Is fiber in the future to the house? Projector? Overhead speakers?