Floni I practice the flip up as you wipe up method with bird bombs. MF's are a tad more resistent to bird bomb stains then lets say tar or dirt stains, they clean up nice. I also swipe and roll my chenielle mitts for each swipe (I know it's anal) but it assures fresh mitt is in contact with dirt at all times.
tmchow, aside from the bird bomb case (where the acid in bird bombs destroys your paint), yes you DO NOT have to QD off dust off your car. BUT we all like our cars to be as perfect as possible and in order to do that we take precautions that MINIMIZE scratching. It prevents worse scratching that might otherwise have occured but it's tricky by definition. We do this by using microfiber, which allows "give" in a fiber sense and it traps dust up in the fibers of the towel. We us it in conjunction with quick detailer in order to provide lubrication, to help dissolve and wetten dirt and particles so that it further minimizes chances of scratching. On my silver car, I can get away with lots of things, I usually just rinse my car off at night and rinse it again in the morning and drive fast.
I friends mom spilled some coffee on his dirty winter BLACK car. She took a paper towels and proceeded to wipe the coffee up in a circular motion. It looks horrible, pretty bad stuff. Now we don't do it that badly here, but MF's laced with QD definately is a good mix of preventative.
I hope that addresses your question correctly. Good luck and happy detailing! Steve