It will take a while for a nut tree to grow. I think ours were 50+ years old and huge! I still remember the one time Annie G made some kind of bourbon chocolate pie (or a similar amazing flavor) for a get-together. So yes, chocolate is good!
I don't know what vegemite tastes like by itself. I think a friend brought it over once in a little packet but I can't remember if we braved a bite or not!