I think you're pressing it, since the airline could require you to actually check in by 2:19 or 2:36, depending on which of the two aforementioned flights you take (easy enough to confirm with the airline), after you've gotten to the airport and returned your rental car, but if you actually are in your car at 1:30 (i.e., not just that the meeting ends at 1:30 and then you have to walk to wherever your car is parked, pay and exit) and traffic, including on Wilshire Boulevard, etc., isn't bad, I think you'd probably make it. Remember, Google Maps doesn't usually take traffic into account.

I like BUR. Small, easy to use, though very limited in facilities, so wouldn't want to kill several hours there.

Clarification to some of the above posts: not all rental car facilities are within walking distance of the terminal at BUR. Avis is, and I think Hertz, as well. But others are not. I have used Budget and Enterprise car rental in the past year and they both required shuttle busses (each is a bit under a mile from the terminal). That is a potential source of delay, as are lines at the check-in counter and security (and, of course, finding a gas station before you return the car). Be sure you know in advance exactly where your rental car facility is, if it's not one of those right by the terminal.

Most of the time, the 405 to the 101 to the 134 (use Google Maps or Mapquest or a GPS) would be fastest. In August we drove from Westwood to Burbank and took Beverly Glen to the 101, but did it as a change of pace. It was not fast, with traffic, traffic lights, etc. At about 3 we hit rather heavy traffic near the 101/134 split (I can't recall the cause). If you find from traffic reports that the 405 is somehwo congested, then, yes, Beverly Glen, or Sepulveda Boulevard or other road over the Hollywood Hills could be used.

At least with LAX there are flights after those getting you to PHL the same day. Could you get out of your meeting before 1:30? If you have never flown out of BUR, it has a bit of a retro feel. No jetways from the terminal. You walk outside. At least it now has ramps to the plane door from the tarmac (as you can see in photos in the link above), not just stairs.