Ach, the dual-wield.. When I originally suggested for the offhand weapon to do 100% damage as well, it was when the trait required 50 points in skill. With such a considerable requirement, 100% made perfect sense, for 50 skill points is a big investment. However, now that one can get the trait already in the first act, it is -with two decent weapons (no roulette here) and a bunch of points put into STR - somewhat overpowered.
Yes, my ranger is a tad vulnerable to hits, even if he's strong, he's slow, but imagine how he's going to slaughter dem bastard mobsters in act 2.

100% offhand still sounds something that
could be awesome in the later chapters, rather than 75%. However, maybe this percentage-increase should be leveled as well?
25% base-offhand damage + 3 percentage point offhand damage increase /level would lead to => offhand dmg= 0.25*primary dmg + (level*0.03)*primary dmg = 100% primary dmg @ level 25, but would not go above 40-50% during act 1. Offhand damage would, of course, be capped at 100%.