Jesus knows he's in a trap. I love the drama of Jesus calling the man to the center. He frames the issue in a way that it is both clear and incontrovertible. Then he looks around very deliberately with grief. . . and heals the man. Sweet! This is very instructive in dealing with difficult people who oppose you on inadequate grounds.
He chose the twelve -- that they might be with him. What a gift! I choose you to be with me. Oh, to be with Jesus. They were chosen to preach and have authority over demons, too.
Mark is the clearest of all gospels about the unforgivable sin. He says, "because they said he had an unclean spirit." He actually has the Holy Spirit. That is the blasphemy against the Holy Spirit to call him unclean. He suggests, too, that Jesus has bound the strong man and is plundering his house. How fun to be in on that!