As to the QF FFP; will this be of use to me back in the UK when I probably won't be flying Qantas again?
Does not matter too much. You can QF use miles to get award flights on BA, AA and other Oneworld Ailines (but pay $ for taxes & surcharges). However you can only upgrade a QF flight with QF points on a QF aircraft (same in general:- AA flight upgrade only with AA miles, BA flight upgrade only with BA miles etc)