1. I agree with you brother! The ninja fragments there are obtainable in Elite Instances so it's useless to buy fragments from survival shop, developers should transfer the unbound (and summoning contract as well) at the survival shop. (i have thousands of points there waiting to be spend). And maybe put some interesting ninjas too (like the GNW ninjas)

2. And about this arena thing, maybe you're playing the Ranked Battle in arena. If yes, well you're really screwed because most of them are using their best of the best teams. On the other hand, the practice arena, it is impossible that you cannot win consecutively, because on my experience. I can win with random lineup(7wins/10battles), literally random that my ninjas cannot do combos even 5 combos.

3. About the Convoy/Plunder stuff. Nahhh, i don't like plundering people and never tried it even once. So, i have nothing to say about here.

~That's all my brothers and sisters! Ciao! :D