So three questions:

1) So I'm a little confused about the damage bonus of Berserker items - is it 200% additional damage (therefore 300% or triple, starting from 100 + 200) or just the plain old 200% damage (double weapon damage)? Triple is quite significant, double not so much as then you may as well be stacking fortifying armor pieces to get extra damage from strength bonuses and find a different legendary item.

2) How does it synergise with drugs like Psycho that add damage resistance? The wikia talks about it taking into account "armor resistance", however I'm unsure if this applies to all damage resistance or just that from armor. Seems to me like a berserker, if not for the fact they're wearing no armor, would want to be shot up with a crap load of drugs.

3) Same as 2, but for Lone Wanderer.

Thank you for your time.

I know having def from perks lowers damage.