Wands are extraordinarily cost effective, for one. Using standard treasure tables, it would be very hard for mid-high level character to not make money just because he goes through 30-40 charges an adventure. Your slightly lower BAB is almost completely offset by a wand of bull's strength (not to mention granting you +2 damage). Magic Missile instead of ragned combat, allowing a more lopsided point buy. Screw your skill investments in jump and climb since you can use spells for those. Feat wise, if you were going to take Improved Unarmed Strike and Improved Grapple anyway, you are only down a single feat and 6 hp (the same you would be down by taking static hp if you were level 12) compared to full fighter. Oh, and you get weapon spec. a bit later. But you've added 5th level cleric and wizard spell capability, monk improved unarmed damage, turning (which means they can take the divine feats), familiar, evasion, MUCH higher saves (+3, +2, +6 at 5th level, the equivilent of more than 3 other feats) and few spells to boot.
The problem isn't that he is overly powerful in a straight up battle. The problem is, why are the other characters in the party? With spiked chain, improved trip, improved disarm, and power attack, there's nothing effective to throw up against him. He can single-handedly take out just about any creature with a CR equal to his level (which is supposedly a challenge for an entire party).