Another WUR problem?
 

Some time ago my car started to die out after it was getting warmed up (aprox. 5 min). This was not just sometimes but every time. After some checking and asking around someone suggested that the cause of my problems could perhaps be a bad WUR. He suggested that I could do one of a few things to test the WUR but one of the tests seemed to fix the problem? It seemed that if I disconnected the vacuum line from the WUR to the air box the car would run fine. I've been running the car like this for the last 6-7 months.

Without having a real understanding of my cars fuel delivery system do you guys think that my WUR was the culprit and do you think that I'm causing damage to my car running it like this? The only thing that I did notice after doing this is that the car doesn’t idle well until it’s fully warmed up. Below is an image of the hose that I disconnected and I have both openings on the WUR and air box plugged.

The line off the WUR top "green" in your drawing is the "outside air pressure" line. Normally it connects to the throttle body or air box above the butterfly. It is not a vacuum line per se. The line off the lower front of the WUR does go through the thermo valve to the throttle body below the butterfly and is a vacuum source.
By disconnecting the top line and blocking it then the WUR pressure cannot adjust for changes in elevation/outside air pressure and the vacuum line below is less effective.

There is no problem or damage in leaving this line disconnected and if your car runs better OK. Your other choice is to reconnect it and make sure it has no leaks, then adjust your WUR which was likely the original problem.

It is also possible that the line was improperly connected and connected to a vacuum source. This would be incorrect so I would check that it was properly connected and has no leaks also.