Yes you can create a new library on the computer and the instructions below explain it.
Yes you can backup with iCloud if you prefer to use it, that is what now makes iPads PC free. You may want to do a little research on iCloud before you rely on that.
If you restore from a backup - it is all or nothing - you cannot select just one file or setting.
If you want to transfer the purchased content on the iPad into a new iTunes library ......
The following was copied from this thread. This is essentially what you want to accomplish.
https://discussions.apple.com/thread/2431472
1) Without connecting your iPad to your computer, start iTunes. Click on iTunes. Click on Preferences. Click on Devices. Check the box next to "Prevent your iPod etc. from automatically syncing." Click OK.
2) Now connect your iPad to your computer and start iTunes.
3) When iTunes starts, right click on your iPad under Devices in the left column. Select Transfer purchases etc.
4) After it finishes transferring all your apps to your computer, right click on your iPad and select Backup your iPad.
5) After it finishes backing up your iPad, right click on your iPad and select Restore etc.
6) After it finishes restoring, left click on your iPad , then click on the Apps tab on top, and check the box next to Sync Apps, then click on Apply below.
If everything on your iPad looks good after the sync, go back and click on iTunes / Preferences / Devices and UN-check the box next to Prevent your iPod etc. The only other thing you may want to check is if your contacts, bookmarks, etc. are syncing correctly now. If not, go to the Info tab after connecting and make sure you indicate which features you want to sync with what sources.
Read this thread and the support links as well. There are apps that you can purchase that will allow you to transfer photos from the iPad to your PC. Look at Photo Transfer App in the App store and you can search for others as well.
https://discussions.apple.com/thread/2739253
This support site will help you with transferring iTunes music to your new computer.
http://support.apple.com/kb/HT4527