Morozov, Nikita, and Elena, all of it is old news. Nikita's issues stem from a bigger issue his own personal insecurities. Zhulin would try to tell him if Lena does something better than you it's a credit to the team, but he could never get that. He would put his efforts into always beating her technically and artistically rather than working on his own unique weaknesses like the twizzles and lifts. He went to Morozov clearly intent on improving and ensuring that he wouldn't be overshadowed by Lena and for years she was ignored until the Olympic season. During that season IMHO, he looked like a man boy trying to skate with a mature woman. So that partnership though having its moments was not sustainable.
As for Ruslan, I respect his efforts, and I will always appreciate Frida and Carmen, but it was to be expected that her skating would regress with him, he is not up to her level. Sinitsina, would have to improve, Nikita, is much stronger than her, ID doesn't happen in a vacuum. Ilinykh's acting skills cannot be matched on ice and her technique is spot on. With all the clamourings of her being out of shape she was really motoring it at Russian Nationals this year, even at the end of the program when Ruslan was struggling to keep up she was still powering through. She needs a bigger, stronger and more mature partner. While I may be a bit fixated on Drozd right now, the fact is he's still a kid and it shows behind the eyes. Lena needs someone a bit more mysterious like her. I want a more mature, sophisticated style for her going forwards. I hope things work out well for both her and Ruslan.