Haha  :)
No problem at all. I´ll keep my fingers crossed that you never mix that up while in flight... oh well... a 707 performing a knife edge would look pretty spectacular  ;)
AFAIR there was a Pilot doing a barrel roll in a 707 at least, but I´m not sure if it was another plane.

Thanks again for your help. I played around with the Fuel distribution a little bit today, and I think I get a grip on it slowly. Next step will be to go properly through the Checklists and try to plan the fuel amount I need for my flights.