I beat the Bomb King by buying those boots that protect against Oil. When I got him down to just over half his HP, I quickened him to death. (He uses Renew around there so it's not worth it to avoid being cheap.)

I got the Zodiac Spear by casting Protect and Shell on my whole party, then taking two of them out of play and hauling ass with the third. (I used Fran, and switched to Ashe when she died.) I healed everyone at the beginning of each area and made it to the room with the Zodiac Spear and switched to Balthier, who uses a shield and has every increase-chance-to-block-with-a-shield augment so he managed to survive a few hits while I poked through the chests. Then I got the hell out of there. xP I should really go back to check out the shop, but I think everything's really expensive so it might be just as well to wait until I have more money.

So yay, I have the Zodiac Spear for the first time ever. xP Now everything gets to be really easy.

Off to the Phon Coast! *points dramatically*