@Suiseiseki There's a wonderful bug that stealing a file from root (say, in /sdcard/Pictures/Screenshots, or on a flashdrive, because for some fucking reason rooting assumes you want that) won't work; even after chown to ua89 or whatever it is, you can't actually open the file, so you can't, for example, scp it to a remote machine.
You could, I suppose, use scp by invoking its path and manually pointing to your key, assuming that doesn't have permission errors.