Hi,
Thanks for your compliments. I never prime figures, whether metal or plastic. The Conan figures were undercoated with GW Abbadon black, painted with GW or Vallijo acrylics then washed with neat Future (Johnson's Klear) with 50 drops of Windsor & Newton black ink per 50 ml of Future then varnished with Windsor & Newton Galleria Matt acrylic varnish. The final result seems like a very tough finish and I don't think the figures will chip.
When undercoating I noticed that on some figures the undercoat was still slightly tacky after 24 h, a bit like what some people report with Reaper Bones figures. This wasn't a problem for me but I wouldn't spray prime any Conan figures just in case this made them stickier.
All the best,
George.