A:AnswerYes you can do both stills and video with this camera.
Video capabilities are somewhat limited given this cameras price, so consider it primarily a stills camera.
If video is a priority there are better options, but if it's an occasional need it does great.
A:AnswerThis does not come with an adapter. The adapter is separate and runs $100+ depending on which one you get. There is no way to use an EF lens without the adapter. There are some packages online with adapters, but they are currently on backorder everywhere last I looked.