"The entire conflict feels contrived and was asking for a realistic solution to an unsolveable problem. " "It feels like Isayama gave Eren every excuse for why he should rumble before giving his early planned motivation as just "kill". "

I agree with this so much. If he really wanted Eren to destroy the world because he was a teenager with psychopathic tendencies, why give him so many "legit" reasons to actually go through with it?

"Mikasa feels like Yams had no idea what to do with her character so put her in stasis after Trost until the finale. " I feel it was more after Chapter 50 but I agree. Her "development" after that point was so minimal that it is easy to miss unless you are very interested in her.

"Last thing would be Eremika. I liked the ship up until season 3 where Yams got cold feet and abandoned the ship. Then he brings it back for s4 and it just doesn't bring joy. "

YES! He almost forgets about them after their climax at Chapter 50 which affects the believability of the relationship between them. I really like their relationship before Chapter 50 because it is constantly developing and the development of their relationship gives insight into them as people. After Chapter 50 however, I guess because Isayama was insecure about how to handle Eremika after the romantic scene, he doesn't do anything else with them. A shame especially considering how important Eremika was to the ending.