I don't need iTunes to manage my apps. I can't use apps on my computer. They're easily managed straight on the device.
I get music from a variety of sources. Not just iTunes. Amazon, YesAsia YouTube and other places. I don't use iTunes to play music. It's too slow. I use Windows Media Player.
When it comes to managing my music, you can use iTunes on your device. But iTunes does not have every song in the world. Or self recorded songs.
So I use Copytrans, you add a new song to your iPod and you're done.
Sounds like you need an android phone. Check out their forums and you will find just what you're looking for.