Looking for an extension that will block websites from disabling right click or text selection.
This extension re-enables the right-click, selection and copy function on website which block those
We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.
Install a JS-blocking plugin (like JS Blocker).
It will likely block other scripts from running too, so you need to customise it. Especially if content is also displayed with the usage of scripts.
Enable Show Develop menu in menu bar (in Safari -> Preferences -> Advanceed)
Credits to Dan for the second idea.