These only seem “vaguely connected” if you haven’t studied them together. IAM and S3 are intricately intertwined and you should understand both at at least an i

These only seem “vaguely connected” if you haven’t studied them together. IAM and S3 are intricately intertwined and you should understand both at at least an intermediate level to work with them in sensitive environments. (Note that IAM has permissions specific to each Amazon service, all documented in detail.) None of the rest of the systems you mentioned gate write access, though certainly if they’re in your production flow you should study and review them as well.