When I was logged into my character, a Monk, during the begining stages of Act 2. When I noticed that there was the jewelcrafter artisan present, which obviously I did not get, and he was level 2. This might be expected functionality as possibly blizzard would keep the artisans for all characters on one account.
However the second issue is clearly a bug.
When I d/e'ed serval blue items, I went to put the contents into my stash. When I opened my stash, there was the items and everything from my other character, a Witch Doctor, and nothing from my stash.
So i believe there to be an issue when linking the character to the stash/artisans.