I love the POANG! Still, I’d skip the bedroom chair — if you don’t sit in that spot now, you likely won’t sit there in the future. Chair ergonomics probably won’t change anything.
Desk chair — yes, assuming that you frequently use that desk.
Dutch oven — if you make a lot of braises, then yes. Watch for sales though. I got a decent enameled iron dutch oven from Target for like $20 and use it just as much as the fancy ones I’ve received as presents. Cast iron pans are good but honestly you might do just as well with a cheaper clad aluminum pan (look at Tramontina line at Wal-Mart if they still carry it). They can perform many of the same functions as cast iron and can be a little more versatile for the home cook. Also, the slightly lighter weight and longer handle makes them easier to handle and clean.
Water bottle — take a tip from an old-timer. Those things have been around for years but we called them Thermoses. No need to spend $45 on one — you can probably find a no-frills one for less than half that price.