No, the Canon EOS R10 does not feature official weather-sealing; it should be protected from heavy rain and dust.
No, the R10 lacks IBIS. It relies on lens-based Optical Image Stabilization (OIS) and Movie Digital IS for video.
The LP-E17 battery provides approximately 430 shots when using the LCD and 260 shots when using the EVF (CIPA standards).
Yes, you can use EF and EF-S lenses on the R10 using the Canon EF-EOS R Mount Adapter with full autofocus support.