iTunes support is in all 3.5.x versions. New downloads should automatically open iTunes when your download completes to make sure that iTunes is aware of your new file.

As far as the upload bandwidth goes, it is strange that you're seeing such large jumps. It's more likely due to your computer being generally overloaded in those moments, so what looks like a lot of bandwidth is really the CPU being so busy that it's unable to take the measurement accurately. We'll keep an eye on this.

On the CPU use, are you sharing a similar number of files as you would before? Among the changes we made, I can't think of any that are candidates for increasing CPU use. Are you sure that your Ultrapeers status was the same with this version as opposed to previous versions??