side effects of unharmed/melee

[Skorm]

i was wondering what was the side effect of these skills, ive seen a lot of players raising it above 60 even though they have swords, so i was wondering why, i know that melee gives you a better chace to dodge whit shields, as well as unharmed to to dogde whit nothing, but what else ? i heard someone talking in IRC about some kind of deffese UA grants, can someone please explain me these effects ?

[sabinati]

it also effects the chance to hit with those fighting styles

[Skorm]

do you know anything bout the deff ? not the shield and dodge thing but something about deff

[Skorm]

also, can someone please explain me the "weight" on skills ?