Hello,
My Photo Stream is taking up too much data on my iPhone. Plus, since I already have all the pictures on my Macbook I don't need them all on my phone. However, if I delete them from my iPhone, will they be deleted from my Macbook as well with or without syncing my phone?
If you've copied the pix from the Stream onto another photo album, be it in iPhoto or Photos, deleting from the Camera Roll (which is where they're really taking up space, the Stream is just an alias) will remove them from the Stream and thus be gone for all devices associated from your iCloud account, but they will not be removed from the other album on the Mac.
My Photo Stream
