There's a huge number of questions before an accurate answer can be given, and you horribly skewed the question, but the answer is generally "yes".

The question was horribly skewed, by design. I'm trying to probe if you think any attempt to help the deserving poor at the expense of the undeserving rich is by definition bad.

You phrase it as $10, but we're realistically talking $3500 per year, because feeding the guy for just one day is useless. Are we also giving him housing? Medical care? Clothing? Where do we stop? Long's UBI plan, if it were inflation-adjusted, would mean giving him $46000 per year annually.

It's just an example. Suppose feeding him for the day would enable him to go to work and actually support himself. I didn't ask as a policy proposal, just to figure out where you draw the line, if you do.

What makes the poor man "deserving", and what makes the billionaire's money undeserved? Or rather, who decides what "deserving" and "undeserving" is?

I'd define it the way people in the Middle Ages and Early Modern period did. They made a sharp distinction between the deserving and the undeserving poor, the latter being poor due to their own laziness and misbehavior, the former due to no fault of their own.

Similarly, does the fact that Musk and Ellison made their money through providing useful goods and services make them more or less deserving of keeping it than someone like Buffet who made it playing the stock market or Zuckerberg, Paige and Brin who made it through selling ads?

There is a reason I like to use Zuckerberg as an example. What he provided, if you leave behind narrow economic definitions of value, has no value or even negative value, to individuals and to society. But he has extracted vast amounts of wealth from that society.

You do know the money you think is there isn't, right, and you have no sense of economics or scale? Go ahead, liquidate all of the assets of the 10 richest people in the US, and redistribute it evenly to everyone in the country. Do you know how much money everyone gets? Assuming that:

I am well aware of that. It wouldn't accomplish anything, and for those who actually provide useful stuff... would put an end to that. I'm not proposing to kill the goose that lays the golden eggs.

a) you actually recover all the money (which you won't because most of it is tied up in investments which will crater in value once you start "redistributing" it) and

I accept this, but I'll point out a technical point: a firesale leads to lower prices, but not to lower value. The value, and normally the price, of these instruments is based on estimates of long-term dividend yields and stock price increases.

everyone in the country gets a 1-time check for..... $4,423.51.

The economic damage done isn't even comparable to the "benefit".

How much are you personally willing to pay to someone you never met but who the government claims is more deserving of your money than you are? And at what point do you consider it theft? And who are you to tell other people when they should consider it theft?

It might be theft, but I find that a facile argument. We do need roads, we need security. This is not a motte and bailey fallacy. This actually brings me to my original point. If it is theft, it is not justified even for worthy goals.

We in Europe have far bigger problems. They take our money and send it to Ukraine and on immigrants. That is theft, because it's not spent on their own corrupt interests rather than that of the people.