I have a foreign university degree and a job offer with gross pay of €54000. Do I need Federal Employment Agency approval, or can I apply for the visa directly?
It depends not only on one's salary, but also on his/her job and education. See, for example, notes on this question for Berlin:
Approval of the German Federal Employment Agency. You need the approval of the Federal Employment Agency if you
- work in a shortage occupation and
- earn less than EUR 4,600 gross per month and
- do not have a degree from a German university.