Well it has taken some time, but the skimmer is operating ideally right now. While I was cleaning it I had disassembled the whole thing, gate valve included. The valve was opened all the way, then closed all the way so I could clean it as thoroughly as I could imagine. I reopened the valve all the way before reinstalling the skimmer, and then spent a while getting it dialed in. I suspect I dialed it in during the wear in phase, then when it reached optimum conditions inside the skimmer, it went wild. Since then, I have not had any problems. There are a couple of modifications to the posted picture above to reduce leaking. Overall the skimmer is close to being the least of my worries. Right now I'm battling hair algae and winning that one too.