Is there a place to insert credits for theme contributors and/or libraries/dependencies/graphics?
If you mean adding to this page http://www.elkarte.net/community/index.php?action=who;sa=credits
The easy way to do that is in the package-info.xml file by using the credits tag like
<credits url="www.simpleportal.net" license="BSD 3" copyright="Simple Portal Team">SimplePortal</credits>
Which will add a line in the Addons Section like
SimplePortal: Version2.4 | License: BSD 3 | Copyright © Simple Portal Team (linked to www.simpleportal.net)
Yep, that's it. Thanks. I didn't see it in the docs (yeah, I know I can edit them, I've just been lazy in logging into my user).