by "others" you mean the White Walkers right?
if so whoever made that shit up is dum

yes, the others == white walkers.

valeryan steel might have same background relation to the fire god, which is the god worshipped in the cities around valerya (where mellisandre comes from). the lineage of the targeryans is related to fire magic itself (how khaleesi didn't get burned in the fire that hatched the dragon eggs for exame)