Great map, great diary, great work! Some notes and questions.

effective trip speed of 200mph

Do you mean maximum or average speed? If the latter, then that is pretty bold for one-hour relations (today, the fastest trip is a 66-minute trip between two out-of-town TGV stations at 263.3 km/h = 163.6 mph), though later on you say that the picture is not that different with 150 mph.

If it is easy to implement, I'd suggest you refine your model with these next simplest assumptions:

1. give 40 km/25 miles and 10 minutes each for the acceleration and deceleration phases (the latter is in reality much shorter, but let's have buffer for city entrances),
   
2. calculate the rest at maximum speed, if you're a bit bolder, 220 mph (which is a bit under the 360 km/h max for the next generation of Shinkansens),
   
3. accept half-hour distances as minimum.

Final point: what about Houston-NOLA, St. Louis-NOLA, Jacksonville-NOLA? All seem to be within the scope of your rules (and all would be great to serve some major sub-million cities along the way, too).

"dives" for High Speed Rail can be more energy efficient than with slower rail, because the train clears the dive so rapidly that it does not have time to lose very much momentum

Hm. The factors to consider here are: steepeness of the passages, the ratio of inclination x mass x g to train resistance (which is chiefly wind resistance) and the sum of both to available tractive effort (chiefly a function of how many wheels are driven). Depending on the parameters, a HST passing a highway exit underpass can be much more and much less efficient than a conventional train. But if the parameters are such that HSTs can pass without velocity change and without having to brake on the descent, there should be insignificant overall energy difference relative to travel on level track (e.g., the descent spares exactly as much energy as the extra the ascent demands).

_{*Lunatic*, n.
One whose delusions are out of fashion.}