Overall nice elemental deck.
Tip for Hondens: Captain Sisay can fetch 5 Hondens in three turns, if she goes for card:Minamo, School at Water's Edge first =)
Not a bad deck. Though, I think there are a number of creatur e upgrades you can make. Here's some things to look at and consider.
Time Elemental could be interesting.
Supreme Exemplar would be great. When it inevitably gets board wiped, you'll have a creature in play after the board wipe happens.
Slithermuse for card draw.
Fruitcake Elemental would be hilarious but very difficult to acquire.
Air Servant could provide a strong level of board control.
Splinterfright might have some synergy with your commander.
creepl I'm inclined to say, no. Sorry, if you've already been given an answer.
My line of thinking is that for it to be face down, it has to be played for it's pre-morph cost of 3 colorless. When bringing it back w/ Horde of Notions you're paying the WUBRG cost. Supposing it said that you may pay it's pre-morph cost in addition to any other costs, if casting it from somewhere other than you hand, then, sure. The Horde's ability undercuts it's morph ability, though, I believe.