This deck looks really nice
Do you think running two
Knight of the White Orchid is just too harsh on the mana? Because the upside to running him is definitely there; seeing how he can get Canopy Vista or Praerie Stream if you're a) on the draw or b) facing Ramp. My idea would be running them over Retreat and one Felidar Cub (or Skyrider Elf; seeing how you might want to nudge the manabase towards White a little).
You might be able to get away with it, but I wouldn't do it. Obviously, no big harm removing the retreat (so 1 is no big deal), but you need additional sources of white mana to support two of them without them often being dead in hand, and that will probably come at a cost to consistency. That t2 2 power thing is a big deal, and this might get in the way of it. Plus, I'd totally run
Consul's Lieutenant if I could, but I don't think that I can. I'm also not sure what ramping helps in this deck, there aren't any big plays to be made. Basically, you want 5 mana, and then you're good to go. I guess 6 mana is also useful, but you don't really need it, IMO.
Anyway, these are just my thoughts, let me know if you try it and it works for you. I'd love to make a version that can support double white 2 drops, so if you crack it I'd want to be the first to know. :-)
Edit: I'm not sure this is the right retreat for this deck, btw. I hadn't really thought about that until just now, lol. Emeria might actually be a better fit here, as the pump effect could be useful to push through lethal faster. I'm not sure. I'd test both at some point.