Good job. I agree that hiruzen knew s/t jutsu, becuase he knows every jutsu that exist within the village and also becuase the fourth hokage taught his body guards FTG and tobirama knew a variant of it. So i see no reason why hiruzen wouldnt have learned it from them as well.
And to the s/t question, though it is possible that hiruzen could have used s/t to handle the tbb, its also possible that he just used enma to smack the tbb out of the village like a baseball.
example:
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lol