I've had similar problems, and it always takes some time and patience to set up the bone influence part. Once you get it, you can do all kinds of things. A foot I've been working on has only bones for the big toe and the other five baby toes, so two sets of bones. The big toe has its own set of bones, and the baby toes have one set. The baby toe set influences all the four small toes so the bend together. While this may not be perfect, allowing all four to wiggle like real toes, it is easy for me to curl up or down all four at once and saves me time.

Never Give Up!