Hi there

As above for skin I would use EZSkin without the question and regarding the specs/fireflies I would try to render up to 20-50 samples if those specs will stays or go away,you need to render that bit longer and sometimes HDR itself can emit those specs,I remember I've tried like TIFF,HDR,JPEG and OpenEXR and I've got best results with HDR and JPEG,with TIFF and OpenEXR I've got something like you have right now

Second thing check maps too

Hope this helps

Thanks,Jura