So among the biggest issues I'm seeing are the following:
1) With only 20 mostly underpowered creatures, sure, you have options to trigger Ephara, but you aren't really pumping out anything all that threatening. God-Favored General, for instance, likely will never untap against a good standard constructed deck - if it attacks, a 1/1 on T3 won't survive or it gets tagged with quick removal. Similarly, I feel like Vanguard of Brimaz will similarly underperform.
2) The enchant/heroic theme is certainly out there, but you're leaving out a LOT of the good heroic options - Fabled Hero, Battlewise Hoplite, and Akroan Skyguard come to mind off the top of my head. You could even explore Phalanx Leader if you like. Similarly, many of the auras you're playing just don't have the power you might want. You definitely want Eidolon of Countless Battles as a 4x for starters... etc.
3) No Detention Sphere?
4) Heliod, God of the Sun actually provides you with a trigger for Ephara whenever you like. Sure, it costs 4, but you can pay it whenever to trigger Ephara. To this end, a more mono-white splash blue deck would be ideal as you can turn on Heliod, access Devotion and Nykthos, and other shenanigans of that nature. You can even slide up the curve to include Elspeth and Angel of Serenity.
5) The auras you have included don't really feature much in the way of colorless mana to be made cheaper by Hero of Iroas. I'm not sure what else to include other than perhaps different bestow creatures, but you might explore some other options.
I think there's some promise here, but I just think you're focused too much on the synergy and not enough on having the power to actually win.
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