This is about the iTunes default of enabling the checkboxes.
This cannot be changed.
But if you are using the checkboxes to decide what syncs or not, it is much simpler to make playlists to decide what to sync.
Am I missing something here?
It would seem so, yes.
Checking that box is NOT the only way to limit what is sync'd.
Create a a playlist of items you want on the iPod (named iPod music or whatever) and drag songs to it.
Connect the iPod and click the Music tab across top.
Select Sync selected playlists.
Tick only the playlist containing the music you want on the iPod then sync it.
Now instead of unchecking items, just add/delete them from this playlist and sync the iPad.
The point is that any song (or movie) dragged into any Playlist, is
automatically "checked" by iTunes. I need iTunes to stop enabling the "check".
No it does not do this. Items added to iTunes are checked when added. Moving them around in iTunes does not check them.
Even if it did this, you are adding songs to a playlist you want sync'd so you would need to check the boxes anyway so...
I create playlists for items I want sync'd and add/delete from those playlists.
The only time I uncheck items are for things I rarely/never want on my iPad/iPod are unchecked such as Christmas music and audiobooks I have already listened to.
In my iTunes libraryI have ~ 8000 songs.
I only have a few hundred unchecked.
I sync ~1000 to my iPod mini and ~250 to my iPod shuffle and ~3000 to my iPad.