[spdbrake]

I think you're correct on the vent, as the FiTech swirl pot I used to have installed the vent line was usually dry but would vent raw fuel if the case pressure deadheaded and rose too high. I had initially left it off but would randomly get a burp of fuel as the engine keyed off.

I later ran my vent line to the existing tank vent line by adding a Tee fitting at the top of the filler standpipe vent pickoff. Much like what bkozlow described in his post.