I hate to ask it because I know it varies greatly from person to person but how long could I expect half a gram of dank to stay in my system?
Nobody can realistically and accurately answer that question because, as you said, it varies greatly from person to person. There are too many variables to take into consideration to arrive at a guess. Only periodic testing with a THC test kit (using the first urination of the day each time) can give you that answer.