Well done! It creates a lot of interesting and powerful combinations. I like the take on the fly speed- it does not give one a permanent/at-will/self-Fly (which is a 3rd level Concentration spell), unlike the Aarakocra. Same with Blindsight.
@Robert W.: Getting this for free first, checking its contents then donating by "re-buying" is always an option. I am rendered speechless of your decision to rate this 2/5 solely because you paid $5 for it on your own volition, while this is tagged as Pay What You Want.
[5 of 5 Stars!]