As usual, this info is gleaned from examining other weapons of the same iLv and then extrapolating the caps from there, so while I cannot 100% guarantee these caps, this method has not failed me yet.

Note1: These caps only apply to 2-handed DoW weapons.
Note2: These caps include the amount of whatever stat is already on the item itself.

iLv70 2-handed DoW weapon stat caps should be...
[Main Stat] : 22 (comes capped if HQ)
VIT : 24 (comes capped if HQ)
SkillSp/Crit/Acc/Parry : 29
Determintion : 20
SpSpeed/PIE : Who cares