Have you considered iTunes Match for music & iCloud Photo Stream for the photos?

There is a total of 4 people in our family and between us we have 5 iOS devices, an Apple TV, a few laptops and an iMac. The iMac is setup as our main digital hub. It contains our master iTunes and iPhoto libraries. Here is our setup:

**Music Setup:**

- We have one Apple ID that all iTunes & App Store purchases are made from.

- The iMac contains a local copy of all our music and is set to sync with iTunes Match.
- All other devises* (OS X and iOS) have iTunes Match turned and do not have local copies of the music files (this has cleared up over 40 GBs form my Air!).

- All devises have access to all the songs and can play them either by streaming or by downloading from the cloud and playing them locally.
- Any added music syncs backup with iTunes Match and is available from all devices (this also works for correcting meta tags).

*One exception is our kids iOS devises, we have iTunes Match turned off on them and sync songs via direct connection to the iMac and manually selecting the songs via a playlist as we don't necessarily want them to be able to listen to all our music. This also makes it simpler for them to find what they want to listen to (they're 6 and 3 years old).

**Photo Setup:**

- iMac contains our main photo library and has Photo Stream turned on.

- All other devises** (OS X and iOS) have their own photo library and have Photo Stream turned on.

- The iMac automatically downloads all photos taken from all devises with Photo Stream turned on.
- All devices have access to all photos that are in the Photo Stream and can add to their libraries if desired (this can also be an issue, as all will see everyone's photos).

** One exception here is that I use a different iCloud account from the others as I use my devices for work and therefore keep a separate photo library. All my devises sync to my iCould account. When I do take family photos on my devises I need to manually add them to the family iMac.