Well, as I have kept mulling this system over, I've decided I like it.
As for not everyone being equal, of course the DM can add or subtract based on such things if they are known. If you make an NPC that is known to be a lazy-good-for-nothing, maybe he only gets 100Exp per year. If you have a self-starter worker, add more.
This system is made for when, in the middle of a game, you have to guestimate the level of an NPC (or the age). The players ask if the old brewer can make masterwork beer? Well, he's been doing it for X years, and it's Y level of danger - so you can guess.
I also agree that BAB is an odd thing for a high level baker to get. But I guess I'll just have to live with that for now. I don't mind HP, I know some really tough old fishermen, and I'm not sure anything can kill one of them!
I also go thinking about an Elven town. With this system, is everyone's grandma an Epic mage? Well, by the table, most grannys are around a 9th level commoner, but keep in mind that they probably started out with an 8 CON. After aging effects she's at 2 CON. That's 9 HP total.
I don't think 9 HP is that bad for a tough old lady.
I think I like it. But I AM going to change the title of the last group of jobs from Dangerous, to Challenging. If you are farming that one plot of land nobody wants (because it's filled with rabbits, has no water, and gets little sun) you are getting a lot of EXP.
-Tatsu