Okay, it's awesome to hear so much advice. I have been given a lot of helpful questions to answer, and I'm going to do some re-working to my designs.
For now, I'll address what I can.
Almost There:
The huge sunroof will have both a thin curtain to dim the light coming in, and a thick insulating blanket to regulate heat. We plan to be awake until tired and to have no sleeping schedule in general. Hopefully that works out, if not we'll have to leave the window covered with the insulation at night.
Due to the lack of sleeping schedule, there will rarely be more than three people in bed at one time, and if someone is having issues with space they will be invited to use a sleeping bag on the floor or across the seats.
I have to agree about the sideways seats causing carsickness problems. There will be curtains for every window in the car, so the window could probably be covered at any time. We are sure to do plenty of test runs before trying to leap into a huge roadtrip though, so problems like that can be worked out along the way.
You are also right that I have not really planned out any necessities. I did not mark out where anything but the refrigerator is going, and at this point that's probably moving too. In a future update I will show the planned height of the under-bed storage. There should be ample space with the planned elevation of the bed. Hopefully the porta-potty does not end up under there.
Seraphim:
Thanks for the feedback, I believe people were having trouble with comments due to a sharing setting on my side, not a platform issue. It should be fixed for everyone now.
Since posting this design the first thing I realized I need to change is the seating. There will be five of us total, including driver and navigator. I will be using a large four-person seat instead of the two seats currently depicted.
Karen:
I do have plans that are probably different than a typical vandweller's, but I have not fully worked them out yet and they aren't that specific. I will eventually make an updated post with more in-depth designs, and will hopefully get even better advice.
Thank you everyone for your thoughts, whether directly helpful or just nice.
I will do further planning and create a new post with better depictions within 30 days at most.
For anyone as excited about this van as I am, I'll have to ask you to be patient. This project will likely not begin in physical form for at least two year from now. It's sad, but I'm not exactly funded to buy and modify a large cargo van yet as a high school sophomore. Hang in there with me.