darthcoin recommends inserting a "cache" step between swap & cold storage. i think it's a good idea, in the long run. in light of ever-expanding attack vectors, the trick is figuring out a great cold-storage do-not-touch do-not-worry setup, so some of the wallets that i used to consider cold, i now consider cache.

as far as stacking is concerned, i do not "buy bitcoin" but make instant payments, or even more simply put i "use bitcoin" for whatever necessary.