Checked luggage shouldn't be a problem in this kind of situation -- if anything having checked luggage could potentially help with making the flight. QR -- unlike BA -- will check baggage onto BA flights even when the QR flight and BA flight are on separately ticketed PNRs.

What I would do is check in with QR and get QR to check-in the luggage onto the QR + BA flights -- thus no need to claim luggage at ARN -- and then check in online for the BA flights as soon as the BA flight check-in opens or whenever else it's convenient as long as the BA boarding pass is gotten via online check-in prior to the check-in cut-off time. [I would do it from my QR flights, as I seem to get some free internet on most of my QR flights as of late.