Yes, it features a dust and splash-resistant structure with a rubber seal at the mount, making it suitable for professional use in varying weather conditions.
No, it does not have built-in optical stabilization (OS). It relies on the In-Body Image Stabilization (IBIS) found in most Sony Alpha camera bodies.
The DG DN version is designed specifically for mirrorless cameras, making it significantly lighter, smaller, and faster in autofocus than the older DG HSM DSLR version.