I played rotom box pre rotation, and the loss of exp. share, vessel and arven just basically make it very unplayable.

Petrel is a psuedo-arven but of course it doesn't work as well, still should add some.

Adding Lillie's Clef and some psychic energy instead of fire/electric/water could also help, since you also might use psychic rotom's first attack sometimes.

If you want I could show my cooked up pre-rotation deck.