Like I said in an other thread, in my opinnion, it's good to dream big, and the ultimate goal of the space habitat (either an orbital space station or a moon habitat) is absolutely reachable. However, it is absolutely not realistic to start designing such a structure right away. We're not even close to have the necessary technology, nor the budget. We have to start small in order to reach our ultimate goal (building a space/moon habitat for thousands of us). A first milestone could be to launch a small commercial low orbit station, like Orion Span is intending to do in 2021. I strongly suggest you to take a look at Orion Span project (introduced here for example: https://www.space.com/40207-space-hotel-launch-2021-aurora-station.html?-newsletter&&-sdc). Such a milestone would have multiple purposes for our project:
(1) We will make money out of a related activity. I call that the SpaceX strategy, whose ultimate goal is to colonize Mars, but is for now developing rockets for commercial use.
(2) We will learn from our mistakes. Our first station will not be perfect: it will come across many issues, and we will tackle them one by one, methodically and rigorously.
(3) We can expand it little by little, by "plugging" new modules to the core station. Say on year 1 we start with a station with a capacity of 4 people (just like Orion Span plans in 2021). We will learn a lot, and correct the potential (and inevitable) technical issues that our station will have. Then, on year 2 or 3 (or more), we launch a second module with a capacity of 5-6 people, that will be "plugged" to the first one, and so on.
(4) In parallel we can allocate a certain proportion of our engineering force to develop a first prototype of station with artificial gravity (most likely a rotational structure). Or a moon habitat prototype.
Anyway, all of this will not be possible until we develop a proper virtual centralized workplace, with a very well structured task management system. I believe before discussing the physical design of a space station, we have to first design the channels through which we will communicate and centralize our engineering efforts.