I’m having trouble editing my playing techniques.
the video I watched says clearly that I can select the technique in the right-side panel, then hit the little pencil icon to edit it.
except the pencil is always greyed out and selecting any playing technique activates some sort of “insert mode” (the technique appears next to my cursor, ready to be deposited into the score.)
Have I accidentally pressed on some feature/function I should not have?
Perhaps the video is out of date. Sadly, it happens. The pencil icon will be enabled when you select a playing technique in the score itself, rather than in the panel.
ah! ok, that’s completely different!
ad if I edit the playing technique this way, will it be edited for ALL instances of that technique? or only for the single one where I edited?
All instances. That’s why I often use PT for text expressions in the score. I can change one and change them all at once.
Try also Library > Playing Techniques