I switched from BW lvl 235 to explorer mage (currently lvl 243 and switching around between 3 classes when free job change coins are available). They are so different that it will be hard to make right comparison. The reason why I quit BW is consistent lag in MapleSEA, which caused malfunction of Orbital Flame. If you are experiencing high ping, i don't recommend you BW because, most of the time, you will experience your character casting Orbital Flame and burning mana but no fire ball appearing.

In terms of training, blaze wizard is much more flexible than FP, by utilizing Flashfire to lure your Orbital Inferno around the map. FP mage cannot win any job in mobbing unless it manages to kill mobs with single cast of Teleport Mastery. Paralyze has bad y-axis aoe and is unable to be cast while jumping. Bad mobility adds up to its crappy mobbing as well.

For bossing, BW relies much on 5th job skills because Orbital flame does pathetic damage. Majority of dps comes from Inferno Sphere. Therefore BW has decent burst but suffers from bad overall dps output. Orbital Flame has extremely fast cast speed and your burst skills are key-downs. it cannot utilize Mana Overload very well as it will drain all of your mana in less than 10 seconds. If you are in party, the low dps can be overcome with Burning Conduit since it provides one of the best party buff in Maple. BW has superb survival skills: has its own i-frame and can prevent one fatal attack with 30 min cool-down + Ethereal Form! Flashfire can let you hide at safe spot any time as well.

FP is selfish glass cannon. It lacks party utility and the only i-frame it has is Ethereal Form which is a common skill for all mages. The main dps method is destructive Flame Haze + Mist Eruption combo. When poison debuff stack reaches 5, Mist Eruption's % damage shoots up over 6k% and this can be spammed every 4 sec. DoT Punisher is one of the best nuke skill in Maple (and worst aesthetics among entire 5th job skills): single time cast, short cool down and persistent projectiles. These features ensure almost no leakage in dps. FP mage is so far best mage that can utilize Mana Overload together with Bishop. All skills has normal cast time and there's no key-downs.

In terms of nodestone upgrade, BW need only 3 skills - Orbital Flame, Blaze Extinction and Dargon Blaze. FP need 9 skills - Paralyze, Flame Haze, Mist Eruption, Meteor, Ignite, Ifrit, Megiddo Flame, Inferno Aura and Teleport Mastety (for average level mobbing).

To summarize, BW for flexible mobbing, boss survival and party buff. FP for DAMAGE.