Mentioning a "person before me" in an interview is a bad idea, because it brings forth associations you might not want. Also, there might not be such a person.
The second and third questions are good, but short tenures could also signify a rapidly growing company (which is something to be wary of, but not for the same reason) like Google in 2006.
"short tenures could also signify a rapidly growing company"
Sure, but if everyone interviewing you are less than a year in, where are all the people who worked here before?
And why are you being interviewed mostly or exclusively by junior team members who haven't proved themselves yet? Is the company entrusting the selection of successful employees to newbies who haven't yet proved they can be such?
An interviewer for a company in the middle of a growth spurt should be able to explain that, quote some enticing growth figures, and mention that "almost all of the original team members are now project leaders and executives... in fact, if this goes well, you'll meet some of them shortly".
The second and third questions are good, but short tenures could also signify a rapidly growing company (which is something to be wary of, but not for the same reason) like Google in 2006.