Is it just me, or is that an awful lot of carapils? I don't use any carapils in my IPAs, and a pound and a half seems like a ton to me. I would also change up the hops schedule slightly by moving the centennial 60 addition, like FSR said.
I have a 10 gallon igloo, so I don't know how much grain and water you can get into the 5 gallon. Someone posted a link to "can I mash it" on this. I'll see if I can find it.
EDIT- here's the link:
http://www.rackers.org/calcs.shtml
Also, 75% efficiency may or may not be what you get the first time. I'd guess more like 70% for the first AG if you're not crushing your own grain.