Yes, Andrew was a threat. They showed they are willing to play. Players on the bottom now have a reason to flip. Joe/Fish could use the three to get each other out. Tasha lost her closest ally so now she has to rethink her game.
Mchappy idk, like i need to know why they went after Savage and not a strategic.threat (i guess it can be because they thought he was the leadervof the alliance)
Savage is a big threat physical wise and social - he has Bayon. He already planted the seeds for Joe to flip (specifically on Stephen). He made it clear he wanted Ciera gone too so he risked their plan. The girls need a "common enemy" and that's in Jeremy/Tasha