2. Seems to be some inaccuracy with UI and certain weapons. Weapons that say "1 AP" in the inventory on attack actually use 2 AP in combat, etc. I assume this is known, but posting it anyway.
Weapons always list their individual attack cost.
If you dual wield, or use a shield, those costs are added up, making it 2 AP.
It's a holdover from the previous game, where initially there was no dual wield, and one-handed weapons would instead strike twice if no shield was used.
It is very much intentional, and it should stay that way.
