How works Passive Perception for elf during Trance?

Is Commander’s Strike melee only?

What would you say the damage die for Nunchaku and Bo stick would be?

If I cast Gaseous Form on my familiar, can my familiar still deliver spells with a range of touch using its reaction?

Can you counterspell a magical triggered trap?

Would bracers of archery work with crossbows?

Would allow Detect Magic a creature under the effects of invisibility spell?

doubt: first sentence on “detect magic” would allow a player to detect a creature under the effects of invisibility spell?
but the user would be able to pinpoint the direction? would he know that there is someone invisible?