toula21 wrote:
1. Can i just restore the messages or do I have to restore the entire backup?
You must restore the entire backup. It's all or nothing.
toula21 wrote:
2.If Irestore the entire back up on my iPad, I assume it will also restore the phone, since they are synched
No, that is not how it works.
The iPhone and iPad each sync to your computer. They do not sync to each other. If you change material stored in iCloud (not an iCloud backup, but actually housed in iCloud), then that material would change everywhere. Messages are not stored in iCloud.
toula21 wrote:
3.what hapens to what I ( have on my phone and ipad-since the restore I choose?Is it overwritten or appended to
Your restore overwrites what is on the device.