Cuba is authoritarian because they have to be. Allende's Chile was not authoritarian, and guess what happened? The US coup'd Allende and installed a fascist dictator who threw socialists out of helicopters and tortured them to death in stadiums. The PKI under Aidit in Indonesia were a peaceful socialist movement. What happened? Aidit was killed, and over a million Indonesian socialists were rounded up and butchered with American backing.
As for the Russian Federation, yes, their government is right wing. Putin is a homophobic capitalist reactionary. If you say this on Hexbear, you will find that everyone agrees. Go try it if you doubt me.
As for China, the more you learn about China and its government the less you'll want to give a simplistic take about China in a thread like this — but the short answer is no, they are not far right. They have some Confuscian cultural baggage but are increasingly progressive on social issues, and after decades of state-sanctioned capitalism to pull in foreign investment and evade the sort of economic warfare that hamstrung Cuba and the USSR, they are, at least ostensibly, adopting an increasingly anti-capitalist posture. As for Xinjiang, again, it's a complicated topic and I'm not an expert, but I do know that a lot of the worst claims have been demonstrated to be bullshit, from sources like Adrien Zenz and Radio Free Asia. Even the UN concedes there is no program of mass killing or organ harvesting. It's definitely still bad, but there's enough bullshit that I really don't want to wade into it here.
"Far-right politics, or right-wing extremism, refers to a spectrum of political thought that tends to be radically conservative, ultra-nationalist, and authoritarian,"
Yes, and China and russia are far right due to the authoritative government. I don't care why the government is authoritarian, oppression is oppression.