most innovation already occurs in the public sector, capitalism just makes sure only capitalists can profit from them.

A great article on exactly this, with a video synopsis as well.

Communism le human nature meme–> ...I don’t think a direct counter argument exists because this shit talking point is so fucking vague, it can mean anything.

The best counterargument I've heard is: "If an alien came down to Earth and watched people play Monopoly, of course the alien would conclude that humans are selfish assholes. If an alien came down to Earth and watched people help their neighbors rebuild after a natural disaster, the alien would come to a much different conclusion." Basically, if your whole environment is determined by zero-sum competition of course "human nature" looks pretty shitty.

Communism le human nature meme–> To counter this one, you basically need to go full socratic method, since their assumptions are that 1. Human nature is fixed and 2. Human nature fits capitalism. These assumptions are incorrect and asking them questions to clarify those assumptions is the way. I don’t think a direct counter argument exists because this shit talking point is so fucking vague, it can mean anything.

The counter to this is simple. They assume that humans are inherently greedy/selfish/liars and self serving etc. Since that is what capitalism rewards capitalism is good. We can actually disprove this with some very basic evolutionary logic. Humans evolved to be tribal, communal social animals. If we were greedy or self serving there would be no reason to band together in tribes. Likewise if we stole from each other. Why develop speech at all if everyone was going to lie for personal gain? Etc. etc. etc. Everything about the human species counters this idea, in fact those tactics are so effective because we evolved to trust and rely on each other. We can see this in other tribal animals as well.

It also helps to ask them to name a socialist country that the U.S. didn't invade, covertly interfere with, sanction, or otherwise try to harm.

I’m not going to blame people for wanting to flee a poor country

Another good point to bring up here is that when people leave poor capitalist countries the media describes them as economic migrants, but when people leave poor socialist countries the media describes them as political refugees. It incorporates a lot of what you're saying but highlights the role the media's pro-capitalist orthodoxy has in amplifying it.