I don't think he does have those memories. Didn't they say 10 & 11 would forget what they did and how they changed things? I have to go back and watch again but I'm pretty sure he doesn't know.
Yes, 9 still tries to help and so did 12. As angry and nasty as he was he risked his life twice to save the Earth. That has not changed. And from the fitz sound the thing was making as it floated away into empty space I would say it is not working anymore. 12 has a different personality, one very different from any we have seen since the reboot and I don't think this one has settle in as quickly as the last two. I think there will be more of a growth period for this one. Remember 10 was cheerful but had a very dark side which seemed to almost disappear with 11. Now it is back and the dark side is the major part of his personality. Also he has lost River, Rory and Amy to death. Not the same a his usual swanning off leaving them to live their lives. I think this one's attitude can be attributed to a build up of pressure which has exploded with 12. I will wait to see where they take us.
All that said, yeah Moffitt is writing him badly.