Syncing iPhone with New iTunes Library/PC

Hi,

I recently managed to damage my laptop's (PC) hard disk and lost all my data. I have therefore got a new hard disk and completed a fresh install of Windows and iTunes. This has caused me no end of problems with syncing my iPhone and I have a few questions before I sync my iPhone with the 'new' library, as I really do not want to lose all my app data. There is still a faint hope that I will manage to recover my iTunes Library file, which I believe would solve the problem, but for now I would like to work on the alternative solution...

Q1. If I managed to recover my iTunes Library file from my old install and imported it into iTunes on my new install, would this allow me to sync with my iPhone as I did on my old laptop?

Q2. Assuming I can't get my iTunes Library file back, is there any way of making my new iTunes sync with my new iPhone without losing the data on it?

Q3. Assuming the answer to Q2 is no.. I have authorised the 'new' laptop and transferred purchases from my iPhone to the laptop using iTunes, including apps. However, when I go to sync apps, it warns me that all of my apps on my iPhone will be deleted, along with their data, and replaced with what's on my laptop. Can anyone tell me if the apps that are now on my laptop include the app data? i.e. does transferring purchases from your iPhone to iTunes also transfer the app data with them? My app data is extremely valuable to me and I really can't afford to lose it. Some of my apps have back up abilities, but most do not.

Q4. Will syncing my iPhone with my new library delete the contents of my SMS app? I've got hundreds of messages on there that are again extremely valuable to me. Ensuring these do not get deleted is my first priority until I know for certain that I cannot recover my old iTunes library.

Thank you in advance for your help and patience! I use my iPhone for everything so this is a big problem for me.