Actually not that easy to lease A330's unless you discount the lease rental down to B737 NG numbers. Similar to what happened to the Emirates A330's in VA. Currently there is a glut of A330's on the secondary market. Most not worth the time to look at.
As for the small doors yes they were chosen so that they could get the paint scheme (which was apparently very expensive). No amount of argument could move the EGM involved they say. 2 of the 5 have the big doors and I think you will find them mostly on LAX-SYD to cover off the freight. The 3 with the small doors will not be worth much when they do get moved on.