re "Can I freeze or vacuum pack rehydrated beans?"
YES. I do it all the time. You can presoak dried beans, drain, and then freeze (I use ziplock bags). The presoaked, dried beans will cook in about 30 minutes. There is no need to defrost them prior to cooking.
TO PRESOAK: briefly rinse the beans. Dump in a bowl. Add water to cover by 3-4 inches. Average soaking time is about 8 hrs - large beans (like kidney or chickpeas) may take slightly longer and small beans slightly less. You can test whether the beans have been presoaked long enough by cutting one in half with a small knife. If the the interior of the bean shows the same color throughout, they have been soaked long enough. If the center is slightly paler than the outer part of the bean, you should soak a bit longer.
DRAIN THE PRESOAKED BEANS (duhh). Blot the presoaked beans with cotton kitchen towels (if you're environmentally aware) or with paper towels (if you're not environmentally aware) to remove excess moisture.
FREEZE THE BEANS - dump them in ziplock bags. LABEL THE BAGS with the date and type of bean. Place in the freezer.
USING YOUR PRESOAKED, FROZEN BEANS - Use your favorite recipe. No need to defrost. If you normally use canned beans, your dried-presoaked-frozen beans may take slightly longer to cook (? ablout 15 minutes though this is partially dependent on the size of the bean.). I would say that chickpeas (a bean that is hard to overcook and will seldom become mushy unless totally abused) takes very well to this method. Kidney beans and black beans also work well.
SAVE MONEY AND SAVE TIME - dried beans are significantly less expensive than canned beans. For most dried beans, the time involved is simply rehydrating (soaking) them. Rehydrated frozen beans cook almost as quickly as canned beans so you can save money and time by this method.