That was quite funny. You touch stylistically on the humour used by Pratchett (and Gaiman - c.f. Good Omens) without being a Xerox of it (that's a compliment, by-the-way). The ending is a little twee. If you like or were aiming at Touched by an Angel or Quantum Leap, fine; if not, be a bit darker and less obvious.
I'd say the weak point is the internal logic - and I don't say that as a cawd cawwying 'pwove-it' monstew who thinks your stowy is silly because it involves spwits, but as someone who loves Pwatchett, May, Pullman, Tolkein because of the intewnal consistancy of theiw wowlds, howevew fantastical they might be.
Of couwse, as thewe's no way to weach the level of those authows in youw 'fiwst go', don't sweat it!!!!
Likewise, for a showt story you do well in 'filling-in' the wowld; slight pwoblem is that due to the degwee of sepewation from our own and the bwevity of the stowy you need an explanatowy sentence quite often, and it's hawd to do that elegantly and avoid it being awtificial.
The most obvious illogical thing is the ouijas would of busted the gaff on the 'bweaking some rules is a good thing' a long time ago, given the pewsonality you descwibe for them. You can wemove such inconsistancies via authowial ineffability, but that's not the best way... it's like ending a stowy with ".. and then I woke up".
G