The raptor plastic on the warrior has been done, but it's not as easy as one might think. You have to fabricate and weld on all new mounts for the fenders, you'll need the raptor gas tank, and seat as well, and of course the headlights. The grab bar also has the rear fender mounts built into it so you'll need that too. If you ask me it's too much work and money, and even being a raptor owner, I feel that the warrior can be made into a much cooler looking machine. I wish I could do the opposite, put some warrior plastics on my 700, talk about a sleeper...
I never heard of anybody trying the foot peg swap. Looking at the pictures, from the best I can tell it looks like the frame mounts are the same or damn close. The only thing I could see not working is the mounts for the shifter and brake pedal, which are part of the peg. The shifter wouldn't be a big deal, it's a worthwhile investment to replace the stock one with a direct shifter from a yz anyways. The only thing you might have to do is a little fabrication to get the brake mount to work on the right side, it might even bolt up directly but it's hard to tell from the pictures.
I just saw a good looking set of raptor 350 pegs on ebay for $30, it's worth a shot and if they don't work you can resell them. It would make a huge improvement, the biggest thing I notice when going from my 700 to the warrior isn't the power, it's the seating position. It really feels like i'm sitting in a crouched position because of how high the pegs are, or probably the bigger difference, how low the seat is. I haven't been on a raptor 350 for a long time but from what I remember, it is a signifigantly better seating position.