Mages, Boom-Up bonus EXP, JUMP etc.

Hey ppl,

I'm thinking of making a mage, most probably a F/P one and I'd like to know a few things:

• Since I'll train it during the Boom-Up timeframe, does it matter if I make the first advance at like... lvl15~20? I mean, losing HP/MP and such.
  
• Main attacks at 4th job after JUMP are misting->exploding and Paralyze? What about I/L: Ice chain->CL?
  
• Is using a reverse staff good enough? I don't wanna bother with elemental weapons at all.
  
• Heh... I thought of a bunch of stuff but once I click the "post new thread" button the ideas just vanish
  

I'll post more if I think of/remember something else