[Tolkien]

The attack added through weapons are not part of the initial value: hence if you equip multiple weapons with different attack values to a commander, the attack values for each weapons varies. Besides that though, the bonuses are already counted in the character screen. So bonuses to attack/defense..heck, protection/precision/magic resistance/encumberance are already counted there (everything from blesses to magic bonuses with the exception of weapon attack (and precision) skill. For example if a Jotun axeman with 10 attack (factoring all other bonuses) has an axe with -1 attack, then the attack will have 9 attack skill. You can determine this simply by right clicking the attack skill.

As for your second question, I believe the hit is random and the percent is 80% body and 20% head (assuming no shield hits), though I might need to check on that. I also think it's irregardless of the mode of attack (though again, I could be wrong on this).