I personally think 2lb of caramel 60 will be too much. I'd cut it in half for a warmer. Let us know how it turns out.
Not necessarily...it just depends on how you define 'winter warmer'. 2lbs of caramel/crystal malts will make it very porter-like and it's not too much by any means. I've done strong porters will well
over 15% crystal/caramel malt and the brews don't even turn out overly sweet...but they do turn out rich as hell!
Winter warmer is (or should be) simply a strong, chewy beer...it can be light or dark, it can be malty or hoppy. It can be spiced or not spiced.
I think the recipe looks fine. The only thing it lacks (for me, anyway) is adequate aging time...I would have started the brew sometime in April or May to allow for the good things that happen over time after the fermentation is complete. But that's just my own bias (albeit one definitely based in tradition).
But other than that, your proposed brew looks pretty tasty to me. I'll look forward to your reports as to how it turns out.