I would like to clarify on some of your terms.
The item you are speaking of adjusting is the wastegate actuator arm. It connects the wastegate to the wastegate actuator, and whichever length it is set to dictates when the wastegate will open.
This is NOT the turbo from an R, but the quickest pic I could find.
The big shiny thing on the left is the acutuator, the actuator arm comes out of that, and then connects to the wastegate.
This is NOT an R turbo either, but gives you an idea of what the wastegate looks like from inside of a turbo. You can see the arm on the top right. When the arm actuates, it turns, which opens up cup looking thing with the arm inside of the turbo, dumping all exhaust out, instead of spinning the turbine, thus getting rid of boost.
So, with all of that said...
Having the wastegate actuator arm adjusted too high or low can cause various issues. So far, to my knowledge, poor adjustment does not BREAK anything, but it can lead to piss poor performance in a few different ways. It can limit boost, bring boost on too quickly, bring it too late.
I will warn you though, my father has gone round and round chasing down a boost issue on his R, and adjusting the wastegate actuator arm can be a TRUE PITA. Even with the tool from iPd, it can be tough to lock in right at 4.5psi.
I hope this helps, some.