Yes, you could choose your occupation, depending on what education path you went on.

No you did not get to choose or even negotiate your salary, it was according to an established distribution. Everything was state owned so I imagine its like everywhere else working for the state.

No, you did not get to choose where you live. There is no personal property concept in communism as it was viewed as a bourgeoise thing. You were allocated living space enough for your family. Before having me, my family lived in a studio, then they were moved to a three room apartment shortly after I was born.

I do not live in Russia but in another former communist state.

Source : asked my mother.

You could choose your occupation to a meaningful extent if you showed aptitude. This did not extend to rural-dwellers, who were denied internal passports until the early 1970's, which theoretically prevented their movement to cities (in practice, many were able to move nonetheless). One should also not omit that during the era of mass incarceration and internal exile coinciding mostly with Stalin's tenure, millions were not able to choose their occupation whatsoever because they were typically doing hard labor (many [but far from all] survivors were ultimately rehabilitated and able to return to their previous occupations after attaining freedom).

Salary was not negotiable - it was prescribed. As a rule you did not choose where you lived. Depending on your clout and connections (dubbed blat in Russian), the period, and the location, you could pass off a dwelling to an acquaintance or angle your way into a desirable spot. This was not, though, per the official system.