I like the idea of pet jobs... but I think FFxi was really boring in the pet area.. sure you had some choices, but as a pet dependent job they never really "grow" or "evolve"
Examples for this;
Dragoon - From lvl 1 you and ur weak looking wyvern take on all thats in front of you, as you grow you gain new spells and abilities, new armour and weapons. your "Buddy" on the other hand looks like the sorry dragon it did when you started, it gets some abilities, but nothing to say "Hey im a ?? level dragon now!"
Beastmaster - Same thing as Dragoon, well I know you always switch pets, I would like to see a more. "Pokemon trainer" you can have a few pets, and train each one to be stronger or grow, maybee from a small tiger cub to a full out mystic looking thing? maybee just an idea.
Puppetmaster seems to be doing good for this, you can change armour and such, and for a puppet it seems to have more personality than living pets... lol.. Im not going to much into this since I don't know much about the PUP job.
well thats a jist of what I was thinking ^^
Main Job: THF
Guild job: Alchemy