I use phpMyAdmin, and can affirm that it's a worthwhile tool. It's free, and not difficult to install, so you won't lose much by trying it out.

It is a potential security risk. The documentation explains two or three methods to protect it. I put it in a password-protected directory, and also used a randomish directory name to make it hard to find.

phpMyAdmin assumes that you already know how to use MySQL. It just provides a GUI for accessing the database(s).

You have to be careful using it. It's easy to change or delete content from the database with a click or two.