Eirik,
-You can choose to keep the CR2s in the folder you want (i create a folder with Time stamp and Name of the thema before importing) having juste the reference in the library
-for me the best way i to to make the editing under LR, by editing i mean to set the "star" and to try some settings to see the result of a potential picture
-after selecting the best pictures, i delete the obvious blured or bad framed (unfortunatly i have a few ;-)
-i delete the really so - so pictures from LR or from Bridge (who manage the rate from LR and vice versa, several weeks after.