@dana-edwards, this is interesting.

The question then becomes is it abuse if someone has a lot of power measured in seductiveness and they use their advantage to get what they want from other people?

I am more comfortable with stating it as "amoral".

Do you think seductiveness is a kind of power which can give someone an unfair advantage?

Yes.

Do you think seduction as a whole is ethical or unethical?

Neither. Different beliefs, different strokes. Some people even demand to be teased else they label you boring.

If you think seduction is ethical what are the rules to follow to make sure it remains ethical and does not cross the line?

Let he/she who's naturally blesssed with seductive weaponries refrain from abusing it, using it to gain unfair advantage.

If you think seduction is unethical then how should you inform people that what they are doing is unethical?

Tell them to their face.

If seduction is unethical only in a certain context but ethical in another then under which circumstances is it ethical?

Bringing human dignity to play. Seducing humans like they have no more than the sexual intelligence of a dog makes it ugly.