My radio station (legal, commercial) dosent even notice pirate or part 15 stations most of the time, as long as they don't interfere with us. Thats the big rule. I actually cannot remember the last time we looked up and legal information that wasnt our own.
if you do it right, the big boys wont even know you are a pirate station, and will be more likely to compare their sound with yours just to see how theyre doing. Of course, I dont live in a heavily populated urban area, its way harder there, but the same principles still apply.