#1) Seems obvious to me. It's not a substance. It's a vibration in spacetime. Think about how humans whistle by creating a wind tunnel. Now imagine that a dragon could do that with spacetime.
Your best attacks would logically be trying to knock out its front teeth, or having the thief stand back and lob peanut-butter crackers at its mouth.
#2) Somebody really needs to make a lich out of that, because then you would have a zombie brain-stealing dragon. :D
#3) Hey, every species has some neurovariant people who can't stop talking about that one thing they're really passionate about. No need to make fun of them.
#5) Kind of reminds me of karma tribbles, who are attracted to negative karma and instantly balance it, which makes bad people suddenly have hellishly bad luck. And if you thought tribbles were trouble, they also come in bear and mammoth size.
#6) The "classy" version of copper dragons is the Magnificent Bastard. You know, kind of like Sherlock Holmes. Which kind of makes me want to add a kobold Watson or something like that.
#8) In my fantasy world of Hallelaine, it's the raspberry dragons that breathe intoxicating fumes. They're small dragons with extremely thick nubbled hide, they eat fruit, and that means they're in competition with big cranky bears. So it's mostly a defensive weapon. Still hilarious when it hits a party and the badass fighter starts seeing pink elephants.
10) So he's kind of like Ogun, capable of possessing a new mount if his current one dies. We're gonna need a lot of salt.
11) And thus very easily distracted with the right kind of bait. We've got one Goth virgin, one giant obsidian mirror, and a pack of clove cigarettes. Hit it!
12) Magpies. We kill it with magpies.
13) This is basically what I did with all the dragons in A Conflagration of Dragons. They use metals and other elements to make armored skin, tough claws, breath weapons, eggshells, all kinds of stuff. The different colors are not separate species but color phases, based on which elements an individual dragon's body uses most efficiently. It's kind of like how some dune grasses use silica to make themselves inedible, or monarch butterflies taste awful by borrowing milkweed compounds. So that's why the dragons are going after treasure all the time.
14) Tch. They would more properly be called Teflon Dragons. They simply exist in all dimensions, so from the bottom of a temporal gravity well it looks like they age randomly. But it's kind of like how a spiral intersecting a 2D world looks like a small circle going in a loop. You're only seeing a fragment of something much larger whose organization doesn't fit into your space.
For my wings are made of tungsten,
and my flesh is glass and steel,
I am the joy of Terra for the power that I wield.
Once upon a lifetime, I died a pioneer,
Now I sing within a spaceship's heart,
Does anybody hear?