I would make the following comment on post 43 and the MP's comments,
In May this year the changes addressed two of the problems, a short turn around in Scarborough which meant either a late departure or a termination at Malton and the clash of two trains arriving at the same time at Malton which is now far less likely as the Scarborough departure arrives first.
There was still a lot of late running, but looking back over my delay replays it was lateness not cancellations. However things seemed to deteriorate again around September and have now reached a point where they are as bad as May 2018 IMO.
I would happily accept a change in York in return for a reliable York Scarborough service even although 75% of my long distance journeys are to Manchester or surroundings. If it was a shuttle to York then I just get the next train out of York, most of these journeys are Anytime returns, so if the core route is disrupted I maybe dont get the train that connected in the timetable, but I dont really care as long I as I arrive in Manchester around my intended time. Coming home same thing applies, just get first train out of Manchester.
As for an Express bus service the problem is the A64, journey times are going to be too long, and to go through Malton is always going to be slow.
I do think the financial penalty for cancellation due to lack of crew should be sufficiently high that it's cheaper to have some staff on standby. Maybe give TOC's say 1 cancellation per week 'free' then ramp penalties so that each cancellation due to insufficient staff is doubled from the previous one. I suspect that given this regime multiple cancellations due to insufficient staff would be a thing of the past.
Or of course TPE could just hand the franchise back.