Once onbusiness points bookings are made you arent able to then uograde then you would need to cancel and rebook. The handy thing about onbusiness is that you can cancel a booking in full providing it is 24 hours prior to departure for a full refund of cash and points.

Also in relation to the points about individuals creating onbusiness accounts there needs to be at least two travellers and a company house number is needed. Again i know probably not that hard to do. What i do know is its quite highly monitered by BA i have seen and heard about accounts set up by individuals and travel agents(they arent allowed onbusiness accounts) which were found and swiftly closed!

***** all opinions are my own and dont represent ba or iag***