There are lots of possibilities. For example: Only allow web connections through localhost and start an x session through ssh. This would require you to install a webbrowser though, so that's another security risk. Perhaps you could set up a VM with a dedi IP and only allow connections from there. (secure it well)

Another possibility would be to first pass a reverse proxy that will request a client-side certificate. That'd make it pretty secure.

A password protected directory is just asking for a brute force through a botnet. Your failtoban won't even block anything because the attacker would only let 1 host attempt a password once per 30 min or per hour. But if he has thousands of bots to his disposal, he can still bruteforce a couple times a second.

That's OK you say. I have a strong password. Don't forget: Each connection and failed login attempts is logged. Your logfile will quickly grow. If you did not set a seperate VAR partition on your disk, your root disk will quickly get full and server will crash. Additionally, it will fill up your bandwith and be as effective as a ddos attack.

Don't use passwords. Use certificates. easier for you, impossible to hack.

There are other methods of course, but these would be my preferred methods. Setting phpmyadmin publically is asking to get your data stolen. Do not assume there are not exploits in the latest phpmyadmin. But don't forget to update it within the first 10 minutes when a security patch comes along, otherwise your data may well already be compromised.