Talking about blacksmiths, tailors, stuff like that.

Were there often old "apprentices" that were just never good enough to move forward?

When someone become a "master" (not sure how that happens), is it assumed that they go and buy a new shop somewhere or were they likely to stay on and work for their old boss. Were there often large firms with many masters working under a single employer?

If there was a person who was born with amazing natural skills in a career that they were able to secure an apprenticeship in, would it be likely that they would end up successful and renown for their craft?