Medallion Trigger: Nah, Luffy is not a normal human but nothing about him is magical
Scent: Definitely smells like the ocean, salt spray, probably a little meat since he's always eating
Pulse Detected (and description): Luffy is the world's worst liar and also VERY UNSUBTLE so yes, go nuts
Gait/Breathing: Description/Opt out Again, totally unsubtle so definitely able to be sensed at all times
Axii: Y, though it might be HILARIOUS if it didn't work just on account of Luffy being hard to brainwash bc he's just that big of a clueless idiot