What if you just made it so you can't use feathers while in guise, possibly reduce feather speed to 60-70% as well I think would be slightly more balanced. Priests really need the feathers because they don't have much (on our own I mean) in terms of getting away from melee(roll, freedom, displacer beast, freedom totem, etc).
IMO it should act like that because it's spammable (locks ofc). Something that is literally spammable I don't feel should be so strong.
I'm not really sure what to do about fear pathing except maybe putting a limit to it. Otherwise if you just have the stand in place or even the blind path someone mentioned you may as well call it polymorph and start making glyphs to make it look cute.
I really liked playing some turbo cleave (enh/war/priest) with friends in wargames this week. Very good pressure, tremor/grounding always a good thing. Hunter/war/priest was working well also. if you play shadow spriest/war/rsham or rdruid would be a great comp I think. But really for the first few weeks of the season you could just do whatever you want to feel it out and see what may work best for you and your cousin. Heck without having teams you could do almost whatever you want. Lot's of freedom now to do various things this season.