Most pro bats that make it to retail carry an actual surname rather than initials. I've seen two or three from players who are very well known and also some obscure ones.
To answer some of your other questions, pro bats usually make it to retail as a result of the player rejecting them, or feeling he already has enough, ie they make five for example and he only wants 4.
I would suspect that the letters are code, and match up to a key somewhere, either an indication on who made the bat, or when, or both.
Out of interest mate, why did you import an Australian Bubble, which as far as I can see is a Ricochet with the word 'Bubble' on the stickers? Obviously if it's a nice stick and you are happy then great, but I'm sure myself or one of the other forum retailers could have got you a great Ricochet or a 'proper' Bubble.
Jake