Hurler Question

[Sugashane]

Here is a bullet style list of information on my situation

I have a large PC who has a strength of 30 (biped). So his medium load maxes out at 2128 lbs.
With Overburdened Heave from the Hulking Hurler (Complete Champion pg. 41) I can throw up to a medium load.
The Warmace is a medium weapon that does 1d10 damage, so its damage by size goes M 1d10, L 2d8, H 3d8, G 4d8, etc
The Improvised Weapon Damage (Complete Champion pg. 159) lists weight up to 400 pounds, but the weight doubles per increase, so 401-800 lbs would do 5d6, 801-1600 lbs does 6d6, 1601-3200 does 7d6, etc.
Sharp weapons also do damage as a weapon of twice its weight (noted with the Improvised Weapon Chart).

So if I have a huge warmace it would do 3d8 damage, but if it was specially weighted (magical) and weighed 3200 pounds, would it do 7d6 in melee as well as if thrown?

[Sugashane]

I don't know if this matters, but Mjolnir (Thor's hammer) weighs roughly 4,000 pounds and does 4d8 damage. So it seems to conflict.

[Cog]

So if I have a huge warmace it would do 3d8 damage, but if it was specially weighted (magical) and weighed 3200 pounds, would it do 7d6 in melee as well as if thrown?
I didn't check your math, but assuming that 7d6 is what the improvised weapon table gave you, then yes, you would - if you wielded it as if it were an improvised lump of metal. No crit range/modifiers, no Weapon Focus: Warmace, etc.