I really like this angle. A lot of fencing footage from the side doesn't really clearly show how the blades interact with each other. This is much more instructive!
It's fine. Just dont fall. Early on, we used to kick sand at each other to distract. It ended when I managed to get it into my training partners eyes through the mesh of the mask. And also there was a lot of sand to clean.
Well, it's a valid target in the military sabre manuals we use for reference. So I guess yes. Not always recommended though as a cut to your opponents leg could leave you open.