A thing to look at would be eurorail/interrail tickets you can get internal ones for cheap but not sure if available for the UK.

The rumble of a class 37 makes it my favourite angine I think

It’s a double edged sword as the trees put leaves on the line that make it slippery and can fall on it for trains to hit. They do stabilise steep cuttings though. Something like soil nails or other erosion control measures, combined with smaller trees and bushes would be ideal however more expensive

Not sure where it is this time but it’s an issue that has come up before on this line

How many cracks are we up to now. I make it 6? Possibly 5?

It’s perfectly achievable, problem is a complete lack of ambition at the top.