Mafia 76. Illumination

Shiva is basically Vesper. In terms of Night Watch, description, and status, she fits the role.

Then yes.

Ideally, if Beatrice kills a Mafia or a Serial Killer, even if they haven't killed anyone, the two-day absence of a Night Watch will be worth it. But the targets you're suggesting are not very good. If there's a small chance that Mental is a Mafia, then I'm definitely sure about my role.