Change UI to move upload photo button out of the way.
UI is poorly laid out. I keep accidentally hitting upload photo as that is the same location as send on mobile version. Runs risk of accidentally sending a photo of yourself to a work group for example. Upload live photo is not something that is required often so could be on other side of the screen. Hitting send is used very often.
It is true that the mobile interface should add a confirmation before uploading something since it can accidentally upload things and by the Screenshots not all countries are allowed to take screenshots of people's faces on skype.
If someone takes a screenshot in the chat the chat owner himself should have enough power to be able to delete that screenshot in the chat.