I would recommend that you make a backup copy of your new LFS system. Boot into your host system, become root,
tar cjf lfs.tar.bz2 lfs
That way if you make a mistake installing something in Beyond LFS you can delete everything on the partition. Boot into your host system, become root,
rm -rf *
tar xjfp lfs.tar.bz2
..and everything's back how it was, no harm done.
Also, I would suggest building BLFS with scripts. You can prepare the scripts in your host system by copying and pasting the commands from your browser then reboot into LFS and run the script. Don't forget to put && at the end of every line, that way it will stop at the first error and you can see what went wrong.