I play like shit and have no clue about a game --> conclusion: the game is unfair.
17 games is not big enough of a sample size. In the mirror, initiative can turn around pretty quickly and you have to adjust accordingly. For mulligan: Altruis and twin slices are essential in the mirror, because Altruis is your only boardclear and swing if you lost the board and twin slices are important for the often decisive trades in the first turns.
If they remove rush, the shaman galakrond will drop from the best one to the worst one. I don' think they will do that. I think Corrupted Elementalist will get hit, maybe it will cost 6 mana. And Mogu Fleshshaper could also be targeted.
I am pretty sure they won't nerf to 6\6s, because that would also kill the symmetry of Galakrond and 6\6s without rush are a joke and don't do anything.