Corvin, whatever helps your girls be safe and heal is a good thing in my book. But chalk me up as concerned too about the picketing. (And I'm from the northwest where someone is ALWAYS picketing something.) I would suggest that you watch your conduct VERY carefully (like the shouting "loud enough to be heard inside the Hall") because it would be an easy task for the elders to get 20-30 people to show up and testify to you screaming abusively and irrationally--in their opinion, theocratic warfare strategy. That could hurt your case.
Perhaps if you intend to do the picketing you could continue video-taping the protest? And tone down your personal volume-- your presence says everything that needs to be said. And especially, I am concerned about what advice your attorney gives you about continuing the picketing.
That being said, I do believe that you in no way want to jeopardize your custody fight. And if it were endangering that, you would postpone your picketing efforts until you had gained full custody.
And also, for the record, I think you are right, even if I'm worried about your timing. If many Halls across America had pickets happening outside their doors on Sundays, the WTS would be forced to make some policy changes.