Nothing goes out until you approve it. Your approval is for exactly what you see: if anything about a post changes afterwards, it comes back here for a new tap.
Connect each account once: you sign in on Instagram's or Google's own page — the password never comes here. Instagram's key lasts 60 days and is renewed automatically; you'll get an alert if a renewal ever fails.
Every approval, connection and post, newest first. This log can't be edited or deleted.