He asks the question "How can we make radical change in America by saying ‘Vladimir Putin is our leader?’, which is a very salient point. He goes on to say that we should strive for socialist leadership in all of our countries. What is so off about that? Seriously?

Nothing is wrong with that in general, but who is he saying it to? Who are these people that only want multipolarity and simp for Putin? His call for socialism is good, but ignores the material reality of today's world in which new socialist construction is not possible without first the decline of US hegemony.

I don't like Shea and think he's quite problematic, but your comment about what Kim is saying is, I think, not a good portrayal.

but just thinking about it for like 20 seconds, this obviously wouldn’t mean supporting reactionary states against the US for the pure sake of it. Would Kim il Sung have supported Hitler? Obviously not.

The USSR and China did ally with other capitalist and imperialist forces against Japan and Germany in WW2. And today's world is largely split into two camps - the US and China. Critical support given to Russia (which while being reactionary still currently plays a progressive role globally in the struggle against US hegemony and is allied to the world's socialist countries, though only out of necessity) is not the same as "supporting Hitler". Putin and Russia today are not equivalent to Hitler and Nazi Germany.

As Losurdo puts it:

we can speak of a struggle against a new colonial counter-revolution. We can speak of a struggle between the imperialist and colonialist powers — principally the United States — on the one side, and on the other we have China and the third world. Russia is an integral part of this greater third world, because it was in danger of becoming a colony of the West.