I dont think you should worry too much about the feathers. When you render it you dont have to draw every one of them.
It's a man/horse, right? It does look a bit petrified, as in still. Raising one of it's hands might help.
I wouldnt worry about the perspecitve either. You will not see a horizon line so you can pick your vanishing point somewhere outside the frame, probably to the right and run some parallel features towards it. If you include strong diagonals crossing each other you will heighten the drama and make it more exciting. Also, clouds of dust can be used to cover any weak areas as can foreground elements like foliage or rubble.
Hope this is a help. I've bodged many a job with half remembered tricks like these. Dont feel bad about it. Embrace the good bits. There is probably enough infomation in your drawing to made a decent picture.
Brutal crits for today,
regrets for tomorrow