for KERNEL in /boot/vmlinuz-*; do
grubby --update-kernel="$KERNEL" --remove-args="rhgb quiet"
grubby --update-kernel="$KERNEL" --args="elevator=noop"
done
This is a collection of techical information, much of it learned the hard way. Consider it a lab book or a /info directory. I doubt much of it will be of use to anyone else.