I've been out of town for a while and havn't had a chance to read this thread. The point about scorching ray not being a targeted spell clears that up, but it still seems too powerful and cheap (in terms of cost) to let an archer essentially attack and cast multiple spells in one round.

If the bow itself was spell storing, you would have to physically strike someone with the bow itself (as an improvised weapon) in order to unleash the spell.