Grey text when you look at the content and lock symbol at the bottom of the screen simply shows that your iPod is set to "automatically update songs and playlists". . If you want to access your iPod directly, play it through your iTunes, connect it to a second computer etc. you just need to change the update method to "Manually manage songs and Playlists" in the iPod preferences. For more detail see this tutorial:
Managing Your Songs Manually
One thing to be aware of with manually updating is that the iPod also has to be manually ejected before the "Do Not Disconnect" message will go away.
Safely disconnect iPod
For info:
iPod 101
The iPod offers three ways to transfer music from your computer. You can select one of the following update modes from the iPod Preferences menu in iTunes (Edit=>Preferences=>'iPod' tab):
1) Automatically update all songs and playlists. This is the default mode, in which your entire music library, including playlists, is automatically synced to your iPod. If the music library on your computer exceeds the iPod storage capacity, you are prompted to select a different update method.
2) Automatically update selected playlists only. With this option, iTunes automatically copies the playlists you have selected to the iPod when you connect it to the computer.
3) Manually manage songs and playlists. You can also choose to transfer music to the iPod manually. This allows you to drag and drop individual songs and playlists from iTunes to the iPod.
