Hi
The effects should only take a few seconds to generate.
I had another look at your uploaded images and note that in no 2 you seem to have a blank black frame positioned in front of the png (which may also have been split) and as the red cursor line is positioned on this black clip the preview doesn't show the video clip as it is hidden.
I would delete the black clip as well as the png image (or the two bits if it was split)
Drag the png from the media list and deop it onto track 2 above the video clip and position the red cursor line in the centre of the png.
You should now see png image, the red IK circle, superimposed on the video clip.
This is what one of your other uploaded pictures showed.
Right click the png and choose Effects. Select the SCALE effect.
The Effects Preview window should show the red IK circle positioned over the background video.
Change the scale values and then the Apply button.
Thats all I can suggest for the moment
I think you may have inadvertantly inserted a blank frame
.
Nat