@MRain - I can explain everything - Ritsu is still considered a danger because of the person he is - I assume the person who now owns the ring is afraid that the other demons would gain favor from Ritsu(Respect, admire, love him, etc.) due to the kindness he shows - That might cause the Demons to turn on him - Especially the ones whos contracts have been freed. He's a danger because Ritsu may weaken the ring's power.
As for the "harm her friends" bit - It was stated that she can only follow orders that she understands - So it's like the message going (Owner) ->(Asmodeus) = "Kill Ritsu." Asmodeus is compelled and will continue to attempt to kill Ritsu. The harming of her friends falls under the clause of "Kill Ritsu" - > "Friends Block Ritsu" - > "If Friends Block Ritsu" -> "Can not kill Ritsu" -> "Kill Friends" -> "Can Kill Ritsu." Even though it was not directly stated for Asmo to harm her friends, she still does so under the "Eliminate Protection" - > "Target Exposed" -> "Target Exposed" = "Can kill Target."
For Dantalion - It's stated that he does nothing beyond the order - It still means that he'll perform tasks that will help him accomplish the order, just not anything to enhance it. It's like "I'll kill a person, which will allow me to kidnap a president," but he won't do a "I'll kill a person, which will allow me to kidnap a president, then I'll kill other people to dissuade from rescuing the president."