Also not sure I'm understanding you right :)
My view is this: the wave function is mere bookkeeping and not anything ontologically fundamental. However the fact that such a seemingly bizarre concept lets you do quantum physics (even if it's not the only way) points to some fundamental questions about the nature of...well, nature.
Of course this is not the only valid view...just one that makes sense to me. Thinking about these sorts of questions is a very fun endeavour.
My view is that OP's text about whether the wavefunction goes through both slits is overly long if the premise is that the wavefunction is only for bookkeeping.
Of course this is not the only valid view...just one that makes sense to me. Thinking about these sorts of questions is a very fun endeavour.