Well, get Trapcode’s Particular and you can have all that. A bit pricey at first, but you will find you can do many wonderful things with it (in addition to bubbles) ;o).
Actually everything after QT 7.0.3 should work fine. Apple simply overshot the line a little by forgetting all their legacy functions when implementing all that H.264 and other CoDec stuff, but problems should be fixed.
Nope, you can’t have multiple versions of QT under one OS. Since QT and its CoDecs runs as a system component every install replace the other files with the same name.