Exporting videos to clear my hard drive

So I've pretty much filled my 4tb g-raid... and I need to free up some space. I'm guessing the best way to do this is to export all of my finished work in the highest quality fashion that I possibly can, so if I need to edit it by adding or removing stuff, I have the best possible piece of video to work from.

Of course, all of the text stuff that I have occasionally within the video is permanent... I'll have to go through that with a fine tooth comb.

Once I'm satisfied that the vids are of an acceptible permanent format, I'll export it and delete my capture scratch... which is a scary premise considering it represents 1000s of hours of work.

Do you guys have any ideas for the export, the settings, or any general reccomended advice for such a massive endeavor?