Don't know how to lighten the vector? While holding CTRL and use the mouse and click on the vector layer. That should create a marquee looking thing around it. Create a new layer on top of it and fill it with white. Set the white to soft light. Use SELECT>Deselect to get rid of the marquee. OR you can just use the lighting options under FILTER>RENDER>LIGHTING

Are the clouds stock? Because Tris already did 75% of this wallpaper's work if you did nothing else but slap stocks in the BG. Coming from a person that whores stocks, I will tell you that in order to make it look like you've made some effort to try and work on the composition. Put a better horizon. And the font for the text looks too playful-ish for the intended mood. I didn't even read it - it was too distracting.

Feathers - they suck. They're too bright for the rest of the wall. They need shadowing. They don't vary in size and are just duplicated and flipped? Looks more like flying pieces of Kleenex Tissues rather than feathers in that case.