Draxinusom

They do nothing when they are not filled up.

The texts of all weapon passives are precisely as follows (I actually have them screenshotted but you can't easily upload attachments here): With restoration staff equippedWhile using a destruction staff heavy attackWith destruction staff equippedWith bow eqiuppedWhile dual wieldingWhile using dual wield attacksWith one-handed weapon and shield equippedWith two-handed weapon equippedI really, seriously, have trouble understanding how these could be named more precise or what should be in doubt about how they are worded. English is my third language, and when I first saw this I immediately understood what it meant. I'm wondering now how it could be worded differently to make it more clear while not writing 20 word setences. The official wording of the second weapon set is "backup weapon set", and it's not even shown on your character, neither sheathed or drawn only the active one is equipped. Although I give you the point for it being in you character sheet. Personally, I have never seen more clear and to the point worded tooltips in an MMO. Almost the only thing left to speculation is some specific terms where you have to know what a "disabled" or "unbalanced" opponent means. That is why your question had me flabbergasted and hence why my reply was worded in the way it was.

It's precisely what any logical thinking person should infer from the text. Passives from the 2H weapon line only work when you actually have 2H weapon equiped (not ready, not in inventory, equipped). Same for every other weapon passives with their respective text. So no, you cannot wield weapon X and have passives working from weapon type Y, where X is not the same as Y. Armor passives generally work always but have a scaling factor to the number of actual armor of that type currently worn. The text makes that very clear and it works exactly like that.