No, the Nikon D3300 records video at a maximum resolution of Full HD 1080p at 60, 50, 30, 25, or 24 fps.
The D3300 is highly efficient, providing approximately 700 shots per charge according to CIPA standards using the EN-EL14a battery.
No, the D3300 is not weather-sealed. It is a lightweight, consumer-grade DSLR and should be protected from heavy rain and extreme dust.
It uses the Nikon F-mount. For autofocus to work, you must use AF-S or AF-P lenses, as the body does not have an internal focus motor.