A couple thoughts from a similarly-experience person (ie, grain of salt to be taken):
1.
Den Protector is mighty expensive for what it is you're ultimately getting.
2. One of the problems with the morph cards is that you pay a premium both in terms of mana and time to gain the effect. The time is more critical than the mana, to be frank: consider whether you might benefit from some type of control-type secondary aspect to the deck, perhaps
Send to Sleep or bounce cards, that will help you deal with aggro decks.
3. Given that the general thrust of the deck is to take advantage of face down/face up mechanics, I think you do yourself a disservice by limiting yourself to Morph effects. You should mix in Manifest effects as well. Consider using
Whisperwood Elemental as your trump/best card, instead of eg
Den Protector.
Hope those thoughts might have been of some help.