No, they don't need a social media account, just internet access. The device has its own email address (you choose it) and then family members send pictures to that email address. The device notifies the receiver that pictures are waiting & who they're from & asks if they want to accept them. If they say yes, the pictures appear on the screen.
You should be able to do this in the settings of your app
Just a mistype
Yes, they will run through a slide show of all photos OR photos sent from one particular person (you can easily select which occurs from the frame).
If you have not recieved your answer to How can I delete a picture here it is. when the picture you want to delete is on the screen tap on it and instructions come up, simply hit delete and it will come and ask if you want to delete it, then tap delete again. I hope that helps.
Where can I download instructions to change military time to regular time