. . . . Can anyone explain how you best choose Movie settings . . .
The general recommendation is to use the same resolution and framerate as the source video eg if your source video is 1920 x 1080 25fps then choose the PAL HDTV 1080i 16:9 25fps option.
However if you are mixing video resolutions and/or framerates then I would choose the majority format.
. . . . the Selection Range Frame disappears before the range has been sized appropriately . . . .
I cannot replicate this
If you do not want to capture full screen click the Configuration button you can then select the frame size you want to capture.
Personally I do not use MEP for screen capturing, I use Screencast-o-Matic
. . . . The "Dotted Screen Capture Frame" : I remember having this issue with other versions of MEP. . . .
That issue is here and is not quite the same as the one you are now having.
The comment about overlay sounds like one of mine - and, IIRC, was referred to getting black recordings from Youtube or certain video players when using screen capture. This is not possible because YT and some players have a 'protective overlay' that gets captured and not the video playing under it.
The image you see on your computer screen is built up in layers, eg for playing a video in a browser starting at the bottom layer would be:- background wall paper, desktop icons, program main window, program panes, video player, overlay layer. IIRC the overlay has an Alpha channel, the browser interprets is correctly and displays it as clear, however screen recorders do not recognise Alpha channel so interprets this as black, thus you see nothing underneath the overlay.
Item 3 - capture options.
These have been simplified over the versions - see image below.
Some of the options are no longer popular eg VCD, SVCD, MySpace.
The current Configuration button allows selection of what was the preset resolutions that you could not adjust in the Configuration dialog in MX and 2013/14.
. . . . What might your thoughts be to this workaround? . . . .
The only thing I can think of is an issue with Firefox I occasionally have where the browser window insists on being the top item.
If I opened for example MEP and then Firefox I could not get back to MEP by clicking the toolbar icon, I had to minimise Firefox then click the MEP window.
In maybe the case the capture frame is there, only under the browser window.