No, this is an EF-S lens designed specifically for APS-C sensor cameras. It will not mount on full-frame bodies like the 5D, 6D, or 1D series.
Yes, the 10mm focal length is excellent for handheld vlogging as it provides a very wide field of view, making it easy to keep yourself and the background in frame.
No, the Canon EF-S 10-22mm is not weather-sealed. It is recommended to use a rain cover if shooting in dusty or damp conditions.