Quote from ironwoman;1170648:
Well, do they get affected by reforges like Fire Mastery reforges?
Meteor Strike is influenced by Magic Attack, Intelligence, and Fire Mastery Damage reforges. Casting Speed and Magic Balance reforges probably work as well but I haven't tested them.
Spellwalk is influenced by Movement Speed (highest source) be it from reforges or Wave Sweeper.
Snap Cast doesn't have any reforges which directly influence its effectiveness.
Magic Weapon Mastery, as a passive skill, is influenced by anything affiliated with bolt magic damage or intermediate magic casting speed (though the latter doesn't stack properly yet).