I'm in a hurry for work. Of course do does not directly translate as for but probably the most natural way to say using hurry
I am hurrying to work? I don't even know if this is proper English, but we surely say it often enough.
I believe it seemed too strange to us without some additional context like using "always", but yeah, I guess it's fine after all. Added now.
"Praca" is the normal word, "robota" is a colloquial one. It often has some negative connotations, may suggest that you don't like your job (although it doesn't have to). You could use it here when talking to a friend, but as the course doesn't teach colloquialisms, it won't be accepted.
"Roboty" in plural is an equally good, if not a better word (than "prace") for some construction works.