I don't know if I somehow misplaced the proper credentials or if something was changed, but I can no longer login at MT.org so that I can update my plugin. I also apparently have no idea what my "password hint" was.

Can a mod here help me with or get someone to help me with that?

The plugin is here:
http://plugins.movabletype.org/mailchimp-signup-form/

It should be under:
username = mailchimp_api (at least it should be)

If anyone can help, feel free to contact me off-site via the email addresses attached to that plugin - I know you need to be sure it's the right person.

TIA