1. I don't think so.2. The three engines handle part of this by throttling each as needed. The gravity wheel can have a counterbalancing wheel as needed.3. A diagram is included showing that all the propellant volume needed4. Yes, it will have radiators, lots of them.5. There are ion propulsion NASA proposals today where analysis shows 6. flat spinning wheel can be pushed through space provided proper balance among drive engines is maintained.
I don't know if to laugh or cry....
...dedicate .27% of its GDP each year to the NASA Enterprise program. …To get some sense of what spending .27% of the GDP each year will mean, consider that between 1963 and 1972, during the Apollo era, the US spent on average .50% of GDP per year as shown in the center column in the table to the right. This is about double the level of spending proposed for funding the Enterprise program.