Brine shrimp "eggs", properly called cysts, should not go bad if stored properly in the refrigerator. If you are concerned about such a thing happening, just have a small reserve supply stashed in a small container in the refrigerator for just such an emergency. Of course, this is based on the premise that you buy only properly stored cysts and not some kept on the LFS's shelf or hook in the store.
I get mine from Brine Shrimp Direct.
While some hobbyists do feed other live foods to their dwarfs, cultures of these can be more difficult to raise than just feeding enriched bbs.
If you have rock rubble in the tank, you could keep mysid shrimp in there and the young can provide an excellent supplemental food source for the dwarfs.
BBS need to be hatched, and then grown out for a day until they develop the digestive system needed to feed, and then be enriched with a suitable product for two twelve hour periods, using NEW water and NEW enrichment for each of the twelve hour periods.
The most suitable product for enrichment is Dan's Food with/without Beta Glucan developed and sold by seahorsesource.com.
