/as RAM no, no, attacking the ground or and object won't work either, it is too similar to someone dropping a bag of rats as a free action, somehow convincing the rats to leave the bag rather than being forced to treat them as having total concealment and having to target the area they occupy instead (the single bag) then using the whirlwind attack to get an attack against every single rat, and using the great cleave feat to get an extra attack at their full base attack bonus at any opponent in range for every rat that they kill and/or knock unconsious...
/as RAM You see, attacking an empty space, is like using whirlwind attack on a bunch of rats you brought with you. They both do absolutely nothing other than to cost you actions. And using combat expertise and fighting defensively to temporarily increase your armour class without having an opponent in melee range and getting a dozen cleaves at your full base attack bonus against the same victim are both completely identical. They are bending the intent of a feat to gain effective stats that are well beyond anything that appears in a normal game.
Oh, and if anyone wants to use my fighter build, feel free. Though as I said, i haven't checked the item prices and don't know how much we are getting at these levels. The important bits are the mithral full plate(10500gp) and the +1 animated tower shield(9180gp), and some means of increasing size(Potion of enlarge person, 250gp each) is also very good. The stat boosters are less important. And remember that if you have multiple opponents, power attack is your friend, because cleaving lets you just keep on attacking until you hit something or miss everything, and with 40 odd damage, the chances of knocking them out of the fight and starting all over again with a new attack are pretty good!