Storms ability says when she attacks to re roll all opponents characters. Any that aren't character faces are places in prep area. Are those dice considered targeted by that ability? Or would it have to state targeted to be considered targeted?....

..in this case Steel is one of those dice and his ability says if he is target a ability deal his attack value in damage to the character that targeted him. So would Storm be targeting him?

It does not target. Targeting is either explicitly stated (see the Africa Priestess version of Storm as an example) *OR* it is implied by indicating a specific, set number (example: choose two characters).

Goddess of the Plains does neither.

There is no interaction. Goddess of the Plains does not target.