1- You should still put up your views, but do so in a gentle and effective way. Sometimes the approach/method is very important in convincing people.
2- You don’t need to commend on each video or comment. Just choose the most viewed videos/comments and put your views there so you maximize the number of persons it will reach
3- Regarding other issues like the marriage of Qasem, it’s best not to confront them or any saying about it because there really isn’t a point to it. People in different cultures like to express their love for the event of Karbala in different ways, so as long as they’re not doing something haram, let them do so. Confronting them causes unnecessary tension and disunity, so it should be avoided