I am up to the Dvali quest when the city is in curfew. For Otar's favors, I didn't kill the shopkeeper back in Golem City but completed the second favor kidnapped Dominik. So it ends up both Otar and Radich are alive and having a conversation in Red Theatre office basement. Stopped playing after this because I am sure whether I should kill them or not I guess they should be killed instead of knocked out I also google about this and found that Koller should be dead already in this playthrough.
If you don't follow through with Otar, he'll attempt to seize control without your support. This leads to him having an argument with Radich. If you say you'll do some things, but don't, then Koller gets murdered.
Even if you've already dispossed of both of them, Miller tells you to investigate for leads. Simply put, when 1 is confronted with a problem such as this, "shoot who you have to, take what you want". I have never left any of them alive, so idk.
What you do with them is your choice. You can wait for their conversation, after which Otar sits down outside at the poker table and never moves again. Radich will just start drinking with the two escorts there. It is possible to never touch them, just leave; the info you needed was in their conversation. It is the same situation as Hengsha 1 was in DX3, where you could just infiltrate the back room of the Hive without convincing Tong, and listen to his conversation, after which you just sneaked out again.
Killing Otar and Radich won't have any meaningful differences for the rest of the game, so it is just your choice. Radich has some goodies in his secret safe in his office, but nothing particularly essential.
