I always found SSH to be secure, but after reading your article I find it even more secure.

One comment though, at the end off the article there is a listing for a loop:

for host in $servers
do
ssh -q -o "BatchMode=yes" $host df -k
done

Just recently I had to use such a loop, but it stranded after processing the first item in the list.
It turned out I had to add the ‘-n’ option in ssh command line.