
MichaelSandar |

At a pound a piece, consider that darts aren't our modern play darts. More like old Jarts or Lawn Darts. I would say they can certainly be recovered so long as there aren't any extenuating circumstances - dropped in water, lava, crushed by something, etc.
A mage could probably carry 20 around, but depending on his other gear and strength, he'd be limited in his other gear / treasure he can carry around. One of the things I like about magic users is that they usually don't carry a whole lot - no armor weighing them down. Makes them good treasure mules if you can keep them safe (and if they have a sleep spell as a backup!)

MichaelSandar |

With their RoF of 3 / round, I usually see M-U's hold on to 9 - 12. Just make sure to watch their range (it's only 15') and they're a d3 damage. If you're playing low level, they'll still be on par with the other classes, but as they advance in level they'll slip behind in their ability to ping an enemy. They just don't have the attack chart to keep up when enemies get to about AC 4 or lower. Of course, by then they have some big number spells too.