Just in case you had similar thoughts or questions I have posted it here:
Q: If a character has Dagger+2 (allows one extra attack per turn), and Two Weapon Combat +1, does this result in three attacks per turn or four?
A: Good questions. This situation never came up in any play testing situation, I never had any players try stacking skills or ask about doing it.
I'd rule it as pick which one skill you want to use in combat, either dagger or two weapon attack.
As to Berserk? This seems to be causing much more confusion than I ever thought possible. It's my fault for assuming the word and notion of Berserk was clear on its own.
So the definition of the word Berserk is
In no way does the notion of Berserk imply a cautious or carefully skilled maneuvering. Going berserk is the antithesis of a skilled attack as it is raw fury. In my own games only starting characters or low ranking foes used berserk as once they got some skill it was not necessary as a manuever. Most players saw going Berserk as making you too vulnerable, especially if archers or slingers were around.
So all of that to say, a player trying to combine their skilled attacks with a Berserk action is misunderstanding what berserk means as a word and why those two things do not go together.
Clearly that's may fault for assuming the term and idea of berserk would be clear.
Thanks for the questions.