You know I've been looking to find a way to fix this. I think your picture 3 shows the exact solution. I will confirm it in a while.
I am saying it because I got this page from SR20 manual for a highport with no EGR. Basically what we are doing is converting to the scheme of a highport with no EGR! I mean our lowports have the EGR just in the middle of the CC and TB. If we want to remove the EGR so than we will just have the TB and CC which is actually the SR20 highport engine with no EGR.
The bottom line of the CC is the same for both - with/without EGR. On the top of the CC there are 3 lines - one of them comes out of the tank. Both others should go into the TB. If any of them is plugged, the CC wont work correctly! This is my understanding.
The picture shows how the CC is connected to the TB on a highport with no EGR. You can't see the bottom line and the tank line.