Unsatisfied with my previous route, I figured out a new one that gave me more time between stations for much more realistic walk and bus times. As far as typical routes for this challenge go, this one's pretty unconventional, to my knowledge. Most people usually start or end with Chesham and Amersham, but I've decided I'd really not like to be stranded out there if worse comes to worse. Here's an updated plan for stop order with a much better and more understandable diagram. The separate black lines represent connections on foot. It doesn't show each and every step but has basic information and looks a hell of a lot better. I've only included the sections of track and routes that are in the plan to make it uncluttered.
For a more detailed list of stops, here's a .pdf of the route. Of course, none of it will actually go to schedule, but it provides a basic outlook on timing and other key factors. I plan on using something like it as a guide during the tubeathon: it's readable, basic and provides only necessary information.