Actually what I really want is to enable the pin so the audio scrolls along as it plays. But it seems like to do that I need to disable quick-play. And to do that I need to right click the timeline. But right clicking there does nothing. All worked fine yesterday, today wasted my 90 minutes trying to figure this out. I am not recording, just trying to play-back and listen. Thanks for any help. Audacity 2.1.0
OK, and now I can’t “Cut” while it is paused. I swear I could do that yesterday. Really appreciate any help so tomorrow can be more productive!
Have to stop playback (rather than pause) before you can edit in regular Audacity.
The DarkAudacity variant (fork) may be different …
Pinned playhead was introduced into Audacity in a version later than the 2.1.0 that you say you rae using - works fine for me in the latest 2.3.2 and the alpha test build I have for the upcoming 2.3.3
Similarly there was no right click context menu for the Timeline in 2.1.0 - that too was introduced later
This works fine in 2.3.2 for me.
But curiously it is now prevented (with a suitable error message rather than just graying out if the command and button) in the alpha test 2.3.3.
This, I think, is a regression bug introduced recently - so I shall be logging that later. So this was a useful bit of QA testing for me 
You can make ther edits, like applying effects, while Audacity is Paused - but doing so wll release the Pause and Play (or Record) buttons.
Peter.
What you should do is upgrade to the latest released version 2.3.2 which you can download from the Audacity website:
2.1.0 is now long-superseded, it was released four and a half years ago.
And keep an eye out for the upcoming 2.3.3 - which hopefully should be out next month (and hopefully with that no-cut-while-paused bug fixed).
Peter.
Logged as P2 regression bug #2215: https://bugzilla.audacityteam.org/show_bug.cgi?id=2215
Peter.