In Germany, after 5 yrs (years as student counted with factor of 0.5), automatically get PR but not compulsory. Main obstacle is to get the first working permit. Some caveats though, namely, you need to have contributed into the social system, no criminal record etc.

Automatic PR after 1st year if you invest 1 million Euros and create 10 jobs.

Dual citizenship not allowed, only in very rare occasions.

Usually no problems with work permits if the company wants you badly enough. Which means pure meritocracy.