Just my take...
The gas mask is going to be a bit problematic. Much better to avoid those areas and low spots since any exposed or wet skin is going to cause significant issues.
I would consider adding the following for communication and creature comfort... Can't let a Earthquake stop you from Crushing Candy
Solar Charging Station
I was a pre-teen the last time that California had large earthquake, were as with Sandy and Katrina I watched the 24 hour news coverage just like everyone else. The major problem in those two were flooding, which I don't recall reading about in the 1992 earthquakes.
Gary's idea with the trash can is excellent. Do you have a storage unit? How about friends/family that live close? Storage units can get a bit pricey, but if you have one close, they are an ideal place to locate a stockpile of supplies. The ones around here are single story sheet metal structures and would pose no danger even if they collapsed on your horde.
In your situation, my primary objective would be to survive until help got to me. The bug-out-bag is a good start, but I would look at places that I could stash some extra food, water and tools.
ETA: If you are looking into hunting I would focus on snares. Easy and cheap to make and really effective with a little bit of knowledge