Barton took the only action left to him after his retalitory request was turned down by leadership. His refusal to grant the waiver forces Wilson off Armed Services and has the same effect he was trying to achieve in the first place. Which means he didn't get the message when leadership turned down his request. IMO he's one skating on thin ice politically, but time will tell.
NOTHING. That's why the headline is wrong.
And how common is it for someone to serve on two major committees? If it's common, there should be no rule. If it's uncommon, why was she getting special treatment that others don't?