Suppress messages while sticking with iTunes 10.7 and iOS7?

Question

There's been plenty discussion about the failures of iTunes 11, and for me there are two and a half things which between them make it a no-go.
1. No iTunes DJ. Up Next, even when resized to the left of the main window in the mini-player, doesn't operate in the same way.
2. Search. I *always* want the top option, which was the default in 10.7, i.e. show me everything that matches. I don't want a big album view with the art. I couldn't care less about the art.
3. I have three sets of Airplay speakers around the house, and 10.7 showed which one was selected (or multiple), so I knew where music would come out. Now the wee icon just shows blue, meaning "will play somewhere, but you can't remember where". So I always have to check by clicking on it. Bizarre, although less crucial than the last two.
But I prefer iOS7, despite the fact that music playback has been mucked around with there - I used to scroll through by artist and then pick an album. Now, when you do that, you can only pick which album of theirs to start with - it plays "by artist", which is infuriating. I know I could go back and search by album, but my brain doesn't work like that.
Anyway. My approach is this. Monthly, I backup the computer and then upgrade to iTunes 11, then sync my phone, then downgrade iTunes to 10.7 as per this tutorial.
http://arstechnica.com/apple/2013/03/how-to-downgrade-from-itunes-11-to-version- 10-7-on-your-mac/
So my phone is backed up but I get a much better iTunes to use during the month. It's annoying, but I tried a month with iTunes 11 and I basically got angry every time I tried to listen to music. The awkwardness comes when adding music - I need to remember to add it to both, but that's not too bad. I also know that sooner or later I'll have to give this game up, but for now it's working.
Final annoyance - I just want to get rid of the following message every time I plug the phone in just to charge it:
"The iPhone [blah] cannot be used because it requires version iTunes 11.1 or later."
As if I didn't know. Anyone know how to suppress those messages?

Answer 1

Problem fixed. I had to go into terminal and delete the Backup folder manually.
We to /Library/Application Support/MobileSync
Deleted the Backup folder in MobileSync using a rm -R Backup command