FrankCos
Loving YTtalk
Looked into GIMP and even after watching a cropping tutorial, I couldn't figure out anything about it. I could do the initial cropping, but when pasted somewhere else, it didn't seem to let me to anything else, and I couldn't figure out how to save it as a different image type or anything.
At this point, I'm thinking I'll just leave the thumbnail and image for this video as just plain white background and black text. It's the only thing simple enough to figure out here.
It sounds like you created a floating layer. Here's a link to help fix that: http://docs.gimp.org/en/gimp-getting-unstuck.html
To save as a different image type simply go File > Export...