I stick to 'footage' and 'right click'. I think (nearly) everybody knows what you are talking about.
'Context click' might be a bit tricky. Not everybody is a computer wizard and also you are also dealing with non native English speaking persons (like myself).
I think footage is the right term here. Media can refer to video, stills, audio, etc. Footage refers specifically to moving images.
Right click is definitely the right term (and a feature long overdue on a Mac).
Thanks Ann. So I can go back to what was normal for me back in the day without worrying about it. That is very reassuring.
By the way, I have read many of your posts, and I would never have guessed that you were not a native English speaker if you had not mentioned it now and then over the years. I have picked up a couple of extra languages over the course of my lifetime, but just for casual use. And they don't stick in my head after a year or two of disuse. Your English is better than many if not most of the native speakers on this forum.