A few questions.

[PcTriumph]

First, I can't seem to find Cernunos anywhere in the labyrinth. B9F seems to be a dead end, or I'm oblivious to the staircase. Also, I retired someone and gained an "enhanced" recruit. Does retiring really do anything but give them 2 extra starting skill points?

[Kaname]

[Maxine MagicFox]

to continue off of the second part that Kaname answered, it goes like this:

Level 30-39 gets 2 skill points and 1 stat gain (which stat increases depends on class)
Level 40-49 gets 3, 1
Level 50-59 gets 4, 2
Level 60-69 gets 5, 2
Level 70 gets 6, 3

These bonuses DO NOT stack.

The stat gains are like this (and I had to look these up, lol)
Dark hunter, Landsknecht, and Ronin stat points go to STR
Protectors get VIT points
Survivalists get AGI
Troubadour gets LUC
Medic, Alchemist, and Hexer gets TEC

Really, in my own opinion, it's just not worth starting over for these bonuses until Lvl 70 when you actually NEED these points. If you've screwed your character up, just rest him. The ten levels are hard enough to gain back without starting at Lvl 1 again.

Personally, though, I completed the game without retiring any character.