No, this lens does not feature professional-grade weather sealing. It is recommended to use a rain cover in wet or dusty conditions.
No, the aperture is fixed at f/11. You cannot stop it down or open it up further; exposure is controlled via shutter speed and ISO.
No, it is an RF mount lens designed specifically for Canon's mirrorless R-series cameras and cannot be adapted to EF-mount DSLRs.
Yes, autofocus works within a central area of the frame on compatible EOS R cameras, though the area is smaller than with wider aperture lenses.