Hybrid Wks

Due to the recent influx of stonetooth swords, my guild and bl have been telling me to go hybrid wk. They told me that during third job I can but points into sword mastery and booster instead of putting them in worthless skills. I would still go to level 100 with bw fire--> bw ice--> charge blow, but after that I should max sword mastery and put 10 points on booster, then get lightning charge for sword. How does this build sound to you guys?

Btw: I do have enough dex to equip a stonetooth now so that wont be a problem