Oh, wow. Those are two commutes! Honestly, I would not advice two people to live in the same house and do those two commutes every day. I mean, maybe I'm being a little dramatic, but that is going to be much worse than it looks on paper (or on a map). Right now, the 405 is under construction so it's worse than usual. It has been worse the past 6 months, so any forums that are dated before that, are not accurate. The construction will probably go at least another year, because it's a year behind schedule. Going south on the 405 in the mornings, and north in the evenings, is the way most people go, which is what you are setting yourself up for. You would almost want to just live in Redondo Beach, because going from Sherman Oaks or Thousand Oaks to Redondo in the mornings would be rough. You will want to live south, and commute north, in the mornings, if using the 405. Either way, it's rough.
I am not Jewish, but there are plenty of Jews in Santa Monica, and moving westward from there. Sherman Oaks would be close enough to other Jews...I get the sense that there are more Jews in neighboring Encino, but they are like 5-10 minutes apart. Thousand Oaks is more suburban....I am sure there are Jews there, but it has a much more suburban feel to it, so you don't see the really observant Jews there, because there is not as much of a village/walkable feel. It feels like the 'burbs to me....just a mix of people, but maybe fewer Jews?