Are the Outer Leaves of the Bamboo Shoot Edible?

Are the outer leaves of the bamboo shoot edible, good for compost or bamboo broth, or useful for anything besides throwing away? It seems that the vast majority of the shoot is not good for eating.

I have several other questions as well. First, when I buy canned bamboo shoots, the canning liquid is both edible and tasty. Is this true of the water used for boiling (as demonstrated in the video), or must it be thrown out? Is it useful for anything else?

What is the best way to identify an edible variety of bamboo growing wild?

And what are the most commonly sold (in nurseries) types of edible bamboo (that is, which types of edible bamboo would one be likely to find for sale in a nursery)?