Thanks for the replies!
I have built track in my youth, and was taught to do so properly by Martin Wynne, for whom I had a part-time job. We used jigs to make turnouts, blades were machined, crossings were hard soldered, machine finished and polished, the standard of construction was very high, as one might expect. I would probably use chairs nowadays, a suitable adhesive would guarantee strength, some exploratory work needed to find the right stuff. I am impressed with the quality of running of compensated P4 motive power and stock, it creates the impression of mass so often absent from what now to me are small-scale models. They seem to have shrunk as I have aged, although I have hand-assembled printed circuits with resistors and capacitors as small as 0.5mm by 0.25mm, it has not been a whole lot of fun. I haven't built a layout for nearly 50 years, but see the job rather differently now. Everything needs to work perfectly. My experiments with P4 wagons demonstrated the ability to hold the road, even if not in the way the prototype does, with very small flanges, even properly-inclined rails do not seem to be much of a help, since true inclination is worn to profile by wheel contact from heavy trains. I am concerned about joints between baseboards, although these can probably be mitigated by some serious engineering. Especially if trackbeds are elevated, which I believe they should be, since I don't want my prototype to exist in a world in which it is the lowest point in a landscape prone to flooding :-).
I make springs, for other work, from music wire. Thicknesses go down very small, 152, 190, 200, 230, 254, 280, 305, 330, 360, 410, 460, 510, 560 microns being standard sizes readily available. the thinner stuff does not require Herculian force to make it assume the desired shape, and it would be my preferred material for fragile parts made from round section, such as handrails, although I would recommend securing it with adhesive. It looks as if it would spring buffers well, as well as wheels. I will find out, I guess.
The RTR EM track would be fine for me, but real track is of a shape which fits where it is laid, and so does not conform to the standards necessary for RTR track to make sense. Pointwork often involves curvature not easily achieved in a standard range. The layout of the sleepers is, to me, less important, but that is a matter of taste and prefered viewpoint.