Response from Sean Schroeder of Mura
Thanks very much for taking the time to write a review. We understand your concerns and have taken steps to improve 2 out of 3, the Admin UI and the Docs. In fact, if you update to the latest version of Mura (released since you wrote this review), Mura 7, you'll find a completely redesigned admin. We hope you find it to be an improvement.
As for docs, we are in the process a completely re-doing them completely. In addition, we'll be supplementing the docs with blog posts to illustrate how to do a variety of things in Mura. Please let us know if there is anything you'd like to see.
Again, thanks for taking the time. We appreciate the feedback.