Are you a doctor or scientist? What is your credential to critique his view.

Perhaps the questions about vaccine safety and efficacy have some basis in the empirical experiences of practitioners and recipients?

The human immune system is vastly complicated and not even close to being fully understood by science.

Is it unreasonable to want intelligent, unbiased answers to reasonable questions, or is that sacrilege "because we already know"?

A fundamental of science is repetition of experiments. This is how we know and verify what we know: it will be true consistently with repetition.

If vaccines are as safe and effective as claimed the sellers and proponents should have no problem defending them. In fact so doing would bolster their position, if they are being honest.