no. 'disqualifies you from job interviews' only applies in very few cases. obviously there will be some discrimination overall, but it's not a serious reason to avoid Germany.
I think the persistent poor performance of certain large immigrant groups certainly is an important issue. It is also true that part of this underperformance may have a genetic cause.
the cognitive performance between rich and poor was the same in the sample they looked at (using their specific test). we know that is not true in general -- richer people are smarter on average.
the idea that an "arab/turkish name" disqualifies you from job interviews is dishonest nonsense. it's also quite separate from sarazin's book, which raises some important issues.
I think the persistent poor performance of certain large immigrant groups certainly is an important issue. It is also true that part of this underperformance may have a genetic cause.