We only stayed in PC (Jamieson Way) for six weeks before moving to Altona, so this is a bit limited, but :
Saltwater Coast is a long way from anything else. It is very self contained, but isolated. It'll take a few years for the building to join it up with everything else.
Sanctuary Lakes is better situated, closer to the shops and schools.
There are more properties in Point Cook itself for rent than anywhere else. The houses are generally very new and very nice, and while there is competition, there is more supply - check out domain.com.au for a comparison between suburbs.
My wife used to drop me at Laverton every morning. Traffic to Laverton can be heavy, esp if the freeway backs up, but most mornings it's fine. There are a small number of roads through PC that feed the freeway (have a look at the street layout on Google and you'll see what I mean), and it doesn't take much to congest them. Train links to the CBD are excellent, and $32 a week, going up a bit in the New Year, but still affordable.
I always thought PC was very safe, but away from the town centre, is very, very quiet in the evenings. As we have kids, we didn't get out really in the evenings.
Hope this is of some help.