What bonuses apply to a Dancing Sword?

[Elric VIII]

I am a hexblade and i have just found a dancing greatsword. I have made it my pact and hexblade weapon. When I send it out, what bonuses apply to it?

1) Would I use my Cha to hit/damage?

2a. If the weapon is inside darkness, would it get advantage vs. an opponent that cannot detect it?

2b. If I am heavily obscured but the sword is not, does the attack get advantage?

3. Does bonus damage from class features (Lifedrinker, sneak attack, imp. divine smite, etc) work on the weapon when it's dancing?

[DarkKnightJin]

I'm not sure if there's proper RAW for this specifically..
It'll probably turn out to be how your DM wants to rule it.

Personally, I'd say yes to the first one and the third one. The second question.. If the blade isn't obscured, it doesn't get Advantage. The enemy can see it, so why wouldn't they be able to anticipate its strikes?

[Deox]

Quick glance:
1 - Yes. The sword uses your attack roll and ability score modifier to damage rolls.
2 - Cannot find RAW at the moment. I would not allow for advantage.
3 - No. The sword only uses your ability score modifier to damage rolls.

[Elric VIII]

Thank you.