Is the abreviation 'Doz' equivalent/interchangeable to 'Prof'?
A "Dozent" is just someone who teaches / gives lectures.

This means every Professor/Prof. is a "Dozent" (if he teaches).

But not every "Dozent" is a Professor (e.g. some people who are working in industry and give lectures as a side job or people who just haven´t made it to "Prof" yet.)