How to configure iTunes for travel with an iPhone?

While I keep iTunes and iPhone on my primary iMac, I'm going to be doing some travel and will need to make adjustments for keeping my iPhone backed up on a new MacBook Pro I'll be taking with me. I do not want to add any songs from my current iTunes library or pictures from iPhoto to the MacBook Pro as these are both already on my iPhone.

However, I need to know how to configure iTunes on the MacBook Pro with just a bare installation so I can keep my iPhone apps in it and make a backup every night, but not lose the pictures and music currently on the iPhone. IOW, I want the iPhone to remain unchanged (keeping the pictures and songs), but simply backup only the apps each night when I plug it in. I'll unplug it after the backup and use a regular charger and switch users on the MBP so my wife can do the same with her iPhone.

The only reason for doing this is insurance while traveling that if we need to restore our apps for any reason on either phone, we'll have the backup on the MBP. I'm concerned that if I uncheck photos and music on the MBP iTunes sync area, I'll lose them both on the iPhone until I return home and sync again with the primary iMac. Thanks for any tips.