The hunt bonus applies to non-standard hunt actions, blood comes from the target of the hunt.
101643
Ritual Scalpel
Unique.
This Nagaraja gets +1 hunt. This Nagaraja can inflict 1 unpreventable damage on a mortal (ally or retainer) to gain 2 blood as a Ⓓ action.
Rulings
Once in play, can be equipped from the minion it's on (rulebook action) by another minion that does not meet the requirements.
The fact it is Unique has no bearing on the burn option. You cannot use the burn option if you meet the requirement, even if you already have a copy of the card in play.
The action provided by this card is considered to be an action requiring the listed clan/sect/capacity/title (e.g. the action provided by Open War is considered an action that requires an Anarch, the action provided by The Gate of Acheron is considered an action that requires Hecata).
The action provided by the equipment to the attached minion fizzles (resolves successfully for no effect) if the equipment is not attached to the acting minion when the action resolves unblocked.