The only F6Fs to carry 20mm cannon operationally were the -5N night fighters, and they only carried two.
Tiny Tims weren't exactly anti-shipping missiles, either. They were basically a 500lb semi-armor piercing naval shell with a rocket motor attached strapped on. I've been asking for these for awhile because the F4U carried them as well (in addition to the centerline pylon for a 2000lb bomb options). The rockets were used against land targets as well as against shipping. In fact, one Allied strategy called for USMC Corsairs to utilize Tiny Tim rockets against German V-1 launch sites in Europe (nixed because George Marshall refused to allow Marines in "his" war, and the Allied land offensive was overtaking the sites, anyway).