Oh dear Twybill - I have clearly explained myself so poorly that you have misunderstood my position to a large extent.
My interest in woodland is in many ways focused not so much on the obvious part - the trees- but on the woodland groundflora. The position with brambles is very complicated, and there are very many factors involved that are very specific to individual sites.
On the whole though I think, from my perspective, it would be a mistake to manage a woodland as you suggest. The negative impact on the groundflora would be too great - and consequently also on the specialist invertebrates that were unique to those plant communities.
It's true brambles are very valuable - good protected nest sites, nectar/pollen and in certain light levels (depending on the canopy) bramble also, as you suggest, can provide good protected regeneration sites for trees (but watch out for the vole years! - ringbarking the young trees at the base whilst protected from predators by the brambles).
I believe a woodland where trees where maintained so far apart that squirrels were unable to jump from the canopy of one to another, and with a ground flora dominated by the sort of very vigorous bramble that would grow under such a permanently open canopy (which I accept would prevent squirrels crossing the ground) wouldn't allow for any of my prejudices about woodland from a conservation or production point of view to be fulfilled.
But each to their own!
I note your coment "Not everyone owns a wood purely for the amount of timber that can be got out." Just over 150acres of our woodland is worked with purely from a conservation point of view, with no intention of production now or in the future. I absolutley accept the continued management (coppicing, selective felling etc.) of our ancient woodlands, in terms of them being maintained as the cultural monuments / artefacts they are (As advocated by Oliver Rackham), but my own perspective is one of "Future natural wildwood" (more in the style of George Peterken - or at least as one of the approachs he would suggest as appropriate in certain specific circumstances).
I think we're probably best agreeing to disagree!