This is fundamentally incorrect.

In my definition, any system where the general public cannot throw out the bums without violence is authoritarian.

Not only is it your definition, but you give no agency to the people. If a socialist state is supported by the public, then that's a good example of a working system. I don't know what you mean by "the bums," if you mean opportunists then every socialist state has had mechanisms to expel party members that were more leech than diligent communists.

The is the fundamental reason communism is not viable. It just swaps distributed power for the even bigger problem of bigger concentrated power.

This is also incorrect. Communism and socialism are both viable, and have been better at distributing power than capitalist systems, including the nordic countries. Collectivization of production and distribution spreads power out to the people, society is run both in a centrally planned fashion and from below.

Just look at happyness indexes. We know the solutions that tend yield best results. They tend to be democracies with a fairly homogenious population and a socialist bent. Capitalists hate this and I assume communists do too because it shows neither is the way.

You're referring to the nordic countries. These are anti-democratic dictatorships of capital that fund elaborate safety nets using the spoils of imperialism. Capitalists love this because they retain their super profits, and communists correctly hate this model because it perpetuates imperialism.

A better word for what? A state?

The bums

Who are "the bums"? Ask a communist, and they'll tell you it's the rich capitalists who run everything. Ask a fascist, and they'll tell you it's jews and brown people. This is the problem with not having a class analysis, without it you're permanently stunted at the childhood level of "good guys and bad guys", with nothing but vibes and latent social prejudices to decide which is which.

The is the fundamental reason communism is not viable. I

China is currently the world power, has lifted over 500 million people out of poverty, and has achieved the fastest increase in average lifespan in human history. The second fastest increase in human history was the establishment of the Soviet Union. As of the last Harvard survey, 95.5% of Chinese people are "satisfied or very satisfied" with their society. To saycommunism isn't viable is, I'm sorry, cope. Communist Cuba has been strangled by embargo for it's entire existence and they still invented a cancer vaccine. Incredible things are possible when money and resources go to something other than a handful of rich capitalist pedophiles.

We know the solutions that tend yield best results. They tend to be democracies with a fairly homogenious population and a socialist bent.

"It is known". And oh look, the old "different races and cultures of people just can't get along happily" racist brainworm rears it's ugly head again, along with the implication that communist governments somehow aren't democratic? The CPC has nine million members, and works by moving proposals up from local councils to national bodies. Meanwhile in our "democracies", corporations write the laws and it's legal for them to bribe the handful of legislators, who speak for gerrymandering districts full of disenfranchised people. Don't forget also that we have the most prisoners and prison slaves of any place on Earth. Last year I watched four riot cops break a college kid's arm right in front of me for the crime of protesting against Palestinian genocide. I say of "capitalist democracy" what Ghandi said of "western civilization": sounds great, when do you start?

It shows neither is the way

I will find whoever wrote that line into The Mandalorian and beat them with soap bars like private Pyle.

Communism and democracy are not mutually exclusive

Your definition is stupid, you should talk less and listen/read more