"I'm not a fundamentalist when it comes to my preferred launchers, but I do believe that a successful commercial RLV will take one of the following forms:"

I think of will be from a process rather than a design. I think a successful RLV will come from suborbital hops less than 1000 miles, to more than 1000 miles, to orbital, to beyond Earth destinations.
And I also don't think the RLV is a essential step in opening the Space Frontier.
RLVs are really a focus in the re-entrying the Earth atmosphere at very high velocity- maybe in short term we think of them more like drag racers- is the focus on a drag racer on re-usability?
Similar to Liberty ships, maybe the focus should on how fast a ship can be built. Can you build a launcher from scratch in less than a month, week, or about even one per day? How many cars are built per day in a auto factory?

It's not going to be a straight path. We will be going to Moon and Mars, and be building space hotels in orbit, and still be doing sub-orbital hops. We could easily have sub-orbital factory making a few sub-orbital vehicles per day at the same time as another factory takes a month to build a ELV heavy lifter for Mars. Having the RLV as THE ANSWER is a NASA mindset; it's like building THE CAR.