Santa Monica is a nightmare of tourists and traffic. No idea why people go there, when there are much better options.
El Segundo is a great under the radar, affordable and very close to the freeway and right by LAX. You can't get more convenient than that, period. It's as equidistant to all 3 events/locations as you're gonna get. There is a pretty cool low-key downtown that's emerged there now (money pouring over from nearby Manhattan Beach), with a cool microbrewery and other quaint local businesses. Speaking of which, Manhattan Beach (right next to it) blows away any beach in or around Santa Monica (and is close), Marina Del Rey, and Venice (obviously). Those are all north and make your trips that much longer and that much more crowded.
If money is no option, just book Shade in Manhattan Beach and don't think twice about it. Wife will LOVE it and you can walk everywhere, including a nice pier (without the Carnival atmosphere you'll be immured in on the Santa Monica pier and it's ferris wheel and vendors galore.
Woah- $900/night. That’s a little out of our range.
I don't know how else to convey it, but I literally said "if money is no option".
I was actually advocating El Segundo, where I know there are spots that are nowhere near $900 a night and it's a very good, central location, given the spots you identified, that will work very well in navigating through traffic to those various destinations. And yes, it actually has a cool downtown area of its own that you'll like, without the madhouse of tourists you will be surrounded by from Marina Del Rey to Santa Monica. I mean, it's night and day the difference. And btw, 10 minutes from the airport. For a shorter trip, less time in the car really does matter.
Most people don't know about El Segundo, which is perfect (besides Mike Schmidt, who grew up there, lol), but that's exactly why it's a great and affordable choice (for YOUR itinerary/trip).