I'm not sure it really proves he's alive - it's a short clip and he remains completely static, no movement at all. If Russia is eager to show he's alive and Ukraine got it wrong they can get him to make a video making it clear that he's alive and well.
It's entirely possible that Ukraine got it wrong, either they've mis-identified someone or it's propaganda, but this video doesn't really prove anything.
Yes.
I'm not sure it really proves he's alive - it's a short clip and he remains completely static, no movement at all. If Russia is eager to show he's alive and Ukraine got it wrong they can get him to make a video making it clear that he's alive and well.
It's entirely possible that Ukraine got it wrong, either they've mis-identified someone or it's propaganda, but this video doesn't really prove anything.