About the kobans, a month ago there was a valentine's event, with 14 days of continuesly koban dailies. Currently another 14 days of continuesly kobans. There will be some balancing later on however as you said it's a small team and the game is far from done. There are people that save up for 900 and some use their 90 kobans. Alot of rng goes into the 90 koban spins. (Not gaining anything from singles instead of savng for 900 - should also not complain - it's taking a risk.)