If this had reach and was aggressively costed, it could be an answer to annoying hexproof aura decks.

Although I think adding reach is doable, feels a little too aggressively costed for a common. I'd happily use that cost on an uncom/rare, though.

Does 'unnattaching' the auras and equipment make more sense, flavor-wise? Or does flavor even matter?

You know, strike that. I'm pretty sure that unattaching auras needs to at least be uncommon for rules complexity issues.

To handle the complexity, it could be unattach the equipment and destroy the aura - identical but clearer. But it's nowhere near as exciting as blowing them both up.

A common that blows up equipment is kinda a powerful statement of "Ok, equipment is too good; HOSE."

Well, ish. Remember there are lots of commons that destroy any artifact; destroying equipment is less good than that.

Yeah, but this kinda says "You've got non-evasion equipment? You might as well not have. At least until you Shock this."

Obviously, this is not a card I'd put in a Mirrodin (Well, New Phyrexia) set. In a random set? Sure (see also Ancient Grudge). it's hardly too much for limited (where it will destroy mroe auras than equipments), and standard will have plenty of ways to deal with an otherwise harmless Gray Ogre.