But I've met a number of religious who engage very strongly with traditions as an intrinsic part of their religious experience, and for whom a separation of tradition and religion would mean a diminishment of both.

I'd probably agree with that, but I wouldn't see the separation of tradition and religion as the same as the separation of tradition and the specificity of belief. But then I'm an Episcopalian, and we're weird like that. We engage very strongly with traditions as an intrinsic part of our religious experience (we're a liturgical, sacramental church, with priests and masses and apostolic succession and all that) but we try to include a huge diversity of beliefs.

So my feeling is that just because something's secular doesn't mean it can't be spiritual. The difficulty is getting something which is both spiritual and inclusive in a world of Christian hegemony and, yeah, I think the best solution is pluralism. Your last ("thinking aloud") paragraph does address a concern with my position, but education would probably be better in a pluralistic world, plus its a premise of my metatheological approach that religion can never provide us with "one true meaning" and thus it is okay when they morph and adapt (from my Christian perspective, I'd call it the influence of the Holy Spirit).