Greg responds...

1. I think for Earth-16, what you see on screen is what you get. Conner is friendly enough with Tim and Bart, but they were in a younger class, and he's closer to/with the folks he came up with.

2. I think you asked this already, so I'm not sure why you're asking it again. I know English is not your first language, but I'm not sure what you mean by "leave". I can't tell if you're asking me an in-universe question about when the show is set, the answer to which would be NO SPOILERS - or a question about when the series will drop in 2020, the answer to which is obviously that it didn't and was never, ever going to be ready in time for 2020. Granted, you wrote this in 2019, so if you would want me to update the question for 2021, the answer is that the show will drop when HBO MAX decides it wants it to drop. And they haven't announced that yet.