According to the d20pfsrd, "All Scarlet Throne maneuvers and stances require that ... He must either have his off-hand empty, or be wielding a weapon two-handed to use this discipline."
If I use a Scarlet Throne manoeuvre that allows me to make a full-attack, may I make an attack with my off-hand as long as that off-hand attack is an unarmed strike (and thus my off-hand remains empty)?
Alternatively, may I make a normal full-attack and include an unarmed strike with my off-hand while in a Scarlet Throne stance without forfeiting its benefit?