I think some of the missions are broken. For instance the get 3 x 3 star one I have 8 or 9 different 3 star and that one isn't unlocking. Also thanks for the little tidbits of info here and there didn't realize what the mission pass was for until someone put that here. Currently I'm sitting at levels 13 to 16 on my team. As for the I'm usually using attack from front or move with close/middle/long range one's currently. My team has changed slightly still using a SMG, and SG but i've swapped one LMG to AR and the AMR to SR since evidently SR fires faster? And I've been farming 1-1 for xp since for material costs it's more efficient. I did do the mission 3-1 for a full materials dump once though got a couple of the 2 star recruit things and a pink one that gave 3x xp. So it's not completely wasteful imo but it does cost about 4 times a mission more for same xp.