I haven't tried it yet but I do know that the Agave is the same plant they use to distill tequila - if you store it in the cupboard long enough it might put quite a kick in your morning coffee
It should be stored like honey. It has a long shelf life. The best one to buy if you can find it is the raw blue agave. I prefer the light. The dark tastes sweeter.
Yes, it's from the Agave cactus, which is the same plant they make tequila from.
I don't use it on phase 1 but I've used it (sparingly) for years as well as stevia.