No [mwcard=MW1C20]Highland Unicorn[/mwcard]? After all it's the national animal of Scotland. But seriously, the Unicorn is pretty dang tight. However, you're already including a very solid core of Holy creatures, and I can't dispute that.
On the [mwcard=MW1E03]Bull Endurance[/mwcard] vs [mwcard=MWSTX1CKE03]Healing Charm[/mwcard] debate, I'm a bigger fan of the charm. Your Priestess gains one life when you reveal it, and you have very tough creatures so you can generally afford to wait and avoid overhealing. On average you'll "gain" the same amount of life from either card, but one costs an extra spellpoint and the other gives your mage a life as well.
Also, the more base life something has the less likely it is that Life +4 will come into play. So on small creatures Life +4 is going to be nearly indistinguishable from healing four damage, but on bigger creatures the likelihood that Life +4 won't come into play.
That's my experience, and it's probably more involved than your new player needs.