Some random thoughts
Vlad (Volodya) seemed like a moral human being, but his backstory and how he got his money is never explained. I guess he was into some pretty shady business back in the early 90s and his rigid demeanor and preaching was a defensive mechanism against his own past transgressions.
Katya generally loved her father. The scene in the hospital wasn't acting on her part- she seemed like she was ashamed of her lifestyle deep down inside and didn't want her father to be hurt by seeing her high or drunk- that's the reason she minimized contact with him. Her decision not to give birth was also a result of her shame- she didn't want to bring a "mini" her into the world because she loathes herself deep down inside.
Elena's son and his wife probably made both the second and third child just to collect the reward the Russian state pays for having children- it can be several thousand dollars. That explains why they waited for so long to have more kids. They're typical parasites who will drink and smoke that money away.
Elena is a false moralist. In Soviet times she was probably a die hard atheist. Now she's religious because it's the fashionable thing to be. Tomorrow, who knows?
BTW, the film would have benefited from some tighter editing. Cut out 10-20 minutes of people walking or making beds and it would have been a masterpiece.