Thanks for your feedback. I was planning to upgrade to TinyMCE 4.5.7 since it's the last version that supports IE8-IE10. So yes it will be done, most probably this week.
For the unmaintained tag, I've asked nothing. So not my decision. As I wrote a long time ago, no new features will be added...
Version 3.3.5 released
Support for bbcode render permissions in reports for post
Fix bbcode map tracking to exclude non-visible posts
Reduce db queries against Bbm table
Fix an incorrect class name
All patches have been provided by Xon - a big thank to him
What you described above this statement is working as intended. If you want to make the content "disappear " for everyone, just set "blank" in "Unauthorised Return". But I do not recommend it. You should set "unparsed content with tags". As an admin, this will let you know who tried to use this...