On the contrary, Beeching and Marples did have a vision for railways in rural and semi-rural areas - that there wouldn't be any, as they could not possibly come anywhere close to paying for themselves.
Well yes, I have to give you that one.
Railway management before Beeching had already been closing substantial route mileage (for exactly the same reason as Beeching did) - M&GN, M&SWJ, Mid Wales lines to Brecon, DN&S (and there were many more) - Beeching merely codified this process and sped things up. It is clear the way Railway Management were thinking - the S&D and GC lines had already been prepared for closure before Beeching. I cannot believe that this was just an ad-hoc policy.
I don't think there is any mystery as to why the 'social railway' wasn't thought of until the bulk of the closures had taken place - it was simply unaffordable for the country to retain all that railway network. If it was, then Beeching would not have been appointed in the first place. The concept of the 'social railway' did not come in until 1967, but this did not prevent closures of the Waverley line, Ilfracombe, Minehead, Swanage, East Lincolnshire and others, of which the Government at the time did not feel it could financially support.
If the circumstances of the time were replicated again today, the same results would occur.
Well, I think we all agree that closures would have continued without Beeching.
The two examples of routes prepared for closure that you cite are interesting ones. I believe that they were run down in conjunction with the regional reorganisation, which saw competing main lines in the same region. By contrast, York - Beverley via Market Weighton had been prepared for rationalisation and automation before Beeching got in. I think that one of the problems with the Beeching era was that the top-down approach gave management lower down the wrong incentives - to try and cut rather than become more economic.
I'm not sure there's a lot of point in debating what lines might have closed had he not been appointed. I stand by my (apparently controversial) observation that Dr Beeching was instrumental in developing the closure policy from the governmental side, before he was appointed Chairman.