1.
Do a backup of your phone.
2.
Do a Backup of your phone.
3.
Do a Backup of your phone.
Then you will be able to be less stressed out because you know even if you manage to mess things up you can just restore your backup.
Having just bought a new laptop, I am looking for help in getting my music, photos & apps across to the itunes set up on the new laptop without wiping everything.
How about just transferring your iTunes data from your old laptop user profile to your new laptop user profile and then just re-authenticate with the iTunes store to satisfy DRM. Then you should be able to re-sync at your leisure.
DISCLAIMER: I've never actually done the above myself, so just going upon my (limited) knowledge of iPhone sync workings. So perhaps someone else who has can pipe in.