This bug still exists in Version 16.0.6369 (June 9).
According to the discussion / answer I linked to on StackOverflow, if you specify a field name in the autocomplete attribute of the input box instead of just "off" then that should fix your problems.
https://stackoverflow.com/a/30976223
So <input type="password" autocomplete="list-id-password" ... />
I'm guessing that you'll want to put the actual list ID into the autocomplete attribute value rather than a generic "mailing-list-password" in case there is one mailing list on the domain with a password then it would autocomplete on the other mailing lists. So "list-10-password" would be the value as an example.
The other one would be <input type="text" autocomplete="list-id-webmailurl" ... />
Chrome isn't auto-completing any other fields on the page so just changing those two should work.
Also, for any list with more than 1000 subscribers, the number of subscribers still isn't appearing at the top of the page when editing a list. This doesn't seem to have anything to do with how much room is available - I've tried hiding the left-pane navigation and went full screen on an enormous monitor - if there's 1000+ subscribers the number does not show at the top of the edit page.