Re hand baggage allowance, whilst there's an allowance the wording on the BA site doesn't imply an upper limit, only that you
may have to check in anything over your allowance.
I don't know if I have to self-report as DYKWIA, however, I have carried on three bags (a rollaboard a duffel bag and a backpack) in F a few times without any challenge, question, or second look.