Video editing workflow : Shall I export small sub clips as individual files from the main clip before final output?
I've never used GoPro Studio, but there's no reason you should have to export out the sub-clips individually to use them in your timeline. It may make sense for you to do that if you want to send the individual files to other editors, but even then, you could just send the raw footage with the project file. Another reason could be if you only wanted to work with a few minutes of the footage. You could export out a sub-clip of what you will work on so that you don't have to work with such a large file. However, if you are taking sub-clips from many different spots in the raw file, just work with sub-clips of the raw file in your timeline.