Unfortunately, none of my childhood friends are close to me today, because I moved out of the area where we all lived a little over a decade ago. For that very same reason, I can't say that my best friend during childhood is my best friend today. We do still chat online once in a long while, though.
To be honest, I think it takes a very special set of circumstances for a group of people to be best friends during childhood and then successfully maintain that relationship as adults. We end up taking different career paths, and in some cases move away -- sometimes just temporarily like when we go to college, other times permanently. I think someone would need to have a close-knit group of friends who all stay locally for their entire lives, in order for them to be able to answer positively to both of the questions that you've posed here.