Currently the Class 20, Class 31/1, Class 37/5, Class 41/1, Class 40, & Class 45/1 are used on the Rail Tours on both East Coastway and Southeastern Express; what I'm proposing is that the Class 52 be added to the substitutions list so it can be used on timetable mode on the two routes. As the Class 52 from the Diesel Legends of the Great Western pack defaults to Air Breaks I can see this being a problem.
Yes, although of course you can use the loco on those routes by setting up an "Off The Rails" scenario.
The scenario editor is no good alternative for Timetable mode, since it takes considerable amount of time to set up a scenario with some AI traffic.
True, which for me is a reason not to spend too much time in creating scenarios. I did make quite a few scenarios for TS, but without an easy way to share them and see other people enjoy them, what's the point in TSW...