how does dualwielding work?

all dualwield types included.

stat change display from dualwielding to 2h or one 1h weapon?
attack pattern and base damage using skills not using a specific weapon?

while we are on it. i find myself using a 30-160 damage weapon over 2 x-50 base damage weapons because of the dps changing for the worst, i don’t know if i should trust the dps or not but i really want to dualwield but at this point im just unsure wether it’s worth the damage change or not because i lack the knowledge of the calculation