I could pretty much go along with all those choices. There are a number of other English/Irish cheeses I could willingly substitute, but a good crumbly Cheshire can really hit the spot.
Tea — want to be more specific. No tea bags. Only loose leaf (and I'd want a bloody pot, too — don't know how you and I would heat the water, mind). And has to be Assam. So Assam loose leaf.
I deeply love Mahler's 2 — love them all, actually — but I think I'd go for 3. Keeps you going for a long, long time. Of all of them, that's the one that I have loved the most.
You can have one book (this is getting like Desert Island Discs, isn't it?) You're not required to have the Bible and Shakespeare thrown in. Which would it be?