I don't believe we need most of these things. I can't say any of your ideas are bad. In fact, any of them would probably be welcomed by the community. I've never been able to drag a team member at all, so I wouldn't mind seeing that fixed.
The one idea which is critically needed is the ability for the league leader to designate team leaders.
While you're already poking around in that code, maybe you can solve one or two of the bugs. Quite often, the league leader's star gets passed on mission entry. Less often, teams are scrambled entirely, multiple members are kicked, or a bunch of people are in the mission but not on the league list. Sometimes, you can't invite to your league because somebody else logged off without quitting the league. Pets are often labelled as if not part of the league, even when their owners are in the league. If a league member enters a TF, AE or Ouroboros mission and then quits the league, nobody else can enter the league's mission. I'm sure there's other bugs I forgot about, too.