Oh, if you can see turbulant water in the clear riser tube , that's too high and it will soon be up there again once the oils from feeding are gone.
You are getting much more flow from the pump and its filling the skimmer much better! That is very good! I do believe that elbow was your problem.
Now, If the gate valve is not open all the way, open it up all the way. If it is open all the way and the water level was still too high, you can do one of two things: The best is to raise the skimmer up higher but that might not be possible. The next thing you can do is turn the air intake down a bit until the turbulant water is again below the clear riser tube. Then let it be.
Ideally, you want to run it with the air intake wide open. But after a few weeks of not skimming, your water quality has probably suffered (this is what happened to me and when I fixed it I had to turn the air intake down because the water was coming up too high even with the gate valve fully open, just like yours). It will start skimming like this and then after a few weeks you can start to fully open the air intake and eventually your water quality will improve to the point where you will have to start to close the gate valve to keep the water level high enough inside the skimmer.
Again, this is EXACTLY what I experience: Once I fixed the pump (like you have) the water was up too high and the only way I could keep it below the riser tube was to lower the air intake and as the water quality improved I was able to opwn it up fully.
You are very close! Hang in there!