I thought it was pretty easy to use Racket libraries (except for macros). When I wrote Anarki's libs/ns.arc, I had trouble, but not this kind of trouble. However, I guess I never really tried to add imports to ac.scm. What do you mean by "it doesn't seem to work"?
It could be that I'm working off a codebase that is missing some functions which Anarki uses to do that (I'm going through and comparing them now). When I try simply xdefing functions from libraries I get errors like "Expected 0 arguments with optional arguments X Y Z and got (args)"