regarding mutiple melee as i understand its a plus 1 on the duel role right? what about wound ?
No because you fight each opponent individually. Each model after the first gets +1 to there combat roll. So if its 3 vs 1 the first fight there is no bonus the second gets +1 the third gets +2.
There is no bonus to wound your opponent.
do you use 2 dices if you have 2 against 1?
You would roll a D10 for each point of your attack statistic. As each combat is fought as a separate combat the +1 to the dice roll is the only benefit you get for a mutliple combat