'Dragonkin are descended from the get of wyrms.'
I can't make sense of this. '... greatest of wyrms'?
I think this demands some guidance on exactly how one gets from a proper dragon to a dragonkin. One time miracle? Repeatable magic spell? Some kind of crazy dragon-sex with humans? Even if it's up to the GM, offer some concrete ideas.
'All dragonkin have the will of their ancestry ...'
Suggest:
'All dragonkin have the iron will of their draconic ancestors ...'
'Dragonkin are cold-mined' should be cold-minded?
Suggest:
'Dragonkin are cold-minded and most warm-blooded creatures have an innate fear of them. Dragonkin suffer disadvantage on X, Y and Z checks for social interactions with warm blood creatures.'
Intimidation is a social interaction, yes? Do they get advantage?
