I agree so much about the Arya bit. It was way too unbelievable that Arya could survive the stabbing from the last episode, and then run and escape and beat the Waif! And it would have been solved if only the makers of the show hadn't got carried away with the stabbing in the first place. Arya should have been hurt, maybe in the shoulder, the arm, but something lighter.
Because we knew she wasn't going to die on that bridge anyway. And someone stabbed on the belly so many times, would likely not survived even with nowadays medical care... even less in ancient Braavos, being just "sewed up" by an actress, after falling to a dirty river, walking around the city, and then waiting who knows how long before being found.
Update. 'Think Tank' also has its review, by John Iadarola and Ana Kasparian.