Should be fine

The nylon won't cause any problems bc it is completely impervious to liquids- won't soak anything. I'm not 100% sure about the angora bc rabbit fur isn't antibacterial, but if you lanolize it well, it should do great!
eta- I usually shoot for 80% wool, but

: sometimes you gotta work with what you have.
As for that bright orange-- you can "muddy it up" by dyeing it with blue or purple koolaid! Test it on a scrap first, but you could get a nice warm brown.
eta again-- check out
http://knitty.com/ISSUEfall02/FEATdyedwool.html for wool dyeing instructions (it's written for yarn, but any wool will take it)