iPhone / iPod music problem
Connect your iPhone to your computer. Once you open iTunes, you will see a check mark on Sync only checked songs in the main window for the device. This will only sync the songs checked in your library for that device (iPhone) and will delete the ones you don't want. 

Make sure that check mark is selected. 

In your iTunes music library, deselect the songs you don't want on your iPhone.

For your iPod, you can leave it unchecked and all your songs will sync. 

This should solve both problems you are having.