I see nothing wrong with changing links to Q&A so that they say "FAQ". Once users click that link and get to Categorized Questions and Answers there is some nice verbage there that explains what it is and distinguishes it from the official perlfaq.
Cleaning/improving that verbage might make sense to help guide users (adding a search box specific to Q&A could certainly help that page) but highlighting Q&A by linking to it as "FAQ" seems like a good course of action regardless of whether they ultimately link away because they want the official perlfaq.