ITunes won't connect to my iPhone 4s?

I got a new computer so I needed to re-download iTunes. Since my iPhone 4s was already used on 5 computers, I also had to de-authorize from all of those computers and just have the new computer authorized. When I signed into my account and got my previous downloads imported into iTunes, there were about 3 albums that had all of the songs from the album, but other albums only downloaded a few songs from an album I had originally payed for in full. So I'm missing some songs on my iTunes account on the computer.
The other thing wrong is I can't edit song info, delete songs, or do anything from my computer with my songs that are currently on my phone. When I try to edit song info, everything is greyed out and doesn't give me the option to even click in the text box. Also, I do not even have the option to delete songs.
It would be a lot easier to delete multiple songs and edit info, but something is wrong. I also don't want to have to resync my phone and lose all of the media that didn't download into iTunes in the first place. Is there anything I can do?
Please help!
Thanks!

Added (1). I also can't add songs to my phone from my iTunes library on the computer.

You discovered the biggest reason Apple sucks. You have so many things going on you need to get one of Apple's tech reps on the phone to work it out for you.