I have completed my ideal commuter rail plan:
This is an ideal scenario where all cities want to participate, all railroads are fine with me using their lines, and of course, unlimited $$$.
The blue line is the existing TRE, and the red line is the planned Tex Rail. The green and yellow lines are my ideas.
The black dashed line would probably be a monorail to the stadium, ballpark, and six flags. However, I'm worried about it's capacity to handle big games (this is the reason the yellow line doesn't go to the speedway). Both the stadium and ballpark have a lower capacity than TMS, though.
The white dots are park and ride stations, and the yellow dots are not. All rail lines would converge at both downtown stations.