Is there a way to selectively sync photos? I find the idea that all of my photos, no matter in which folder should automatically be synced to G+ a bit ridiculous.

Is there a way to only sync a certain folder/album? I'm mainly interested in syncing my camera roll.
Launch G+ Photos app. Swipe right on the left edge to open up the menu. Go to "On Device". You can select which folders to be synced by tapping on the cloud icon on the right of the folder name.

Note: You have to turn on "Back up local folders" option in settings. Initially, all folders will be synced and you can  selectively turn off for each folder in the "On Device" section.