The film is a very successful example of Slowly Slipping Into Evil - a hero falling until he eventually crosses the line in his own eyes. You come away feeling sorry for him. But upon further thought, most viewers probably realize Yuri's excuses are paper-thin. He deliberately perpetrated wars long after he had enough money to be comfortable. But that's the point - Yuri's a salesman. The film is him pitching to you. And he convinced you. But like any salesman, he left big chunks out of the narrative because they'd be inconvenient for him.
With this in mind, a lot of the narration makes more sense. Yuri is funny and charming, but that's because it's his job. He knows how to be funny and witty and charming and even vulnerable in just the right ways where you wanna be on his side.
This also explains how he talks about his weapons. Amongst other things, he says the .357 Magnum can never jam, even though it can, on occasion, albeit much less than a traditional pistol. He also gets one or two facts about the AK-47 wrong (the USSR never had it on its currency), but of course, he's repeating the mish-mash of pitch points and mythology that make the merchandise attractive.
The director didn't pay too much attention to making the different eras period-accurate in terms of clothing or the actors aging. But it should be remembered that this is Yuri's retelling of his life. He's thus skimming over the details of how things looked in his memory.
While he's high on Brown-brown, Yuri encounters a hyena, and they just stare at each other for a long time. One is an opportunistic predator who profits from the misfortunes of other creatures. The other is a hyena.
