Negative income tax? Does that mean the government pays me to work?

I think something like this already exists in the U.S. It's called the Earned Income Tax Credit. Low income people may get a tax credit that could result in a bigger refund. Effectively, some people are getting money they woudln't be getting without working. It makes a lot of sense, imo.

https://www.irs.gov/publications/p596

The U.S. Government also pays farmers not to grow crops! See, e.g., the Conservation Reserve Program (https://www.fsa.usda.gov/programs-and-services/conservation-...).

And Electric PUCs pay crypto miners not to mine, tens of millions of dollars, more than what they earn from mining.

Have you got a source for this?

Yeap. In fact, it's a more affordable option than UBI and already (partially) implemented across several countries.

Yes-ish.

But your employer knows. And he might immediately apply "you'll need less money from me, now" logic.

True, but that part only makes a significant difference if the unemployment rate is quite high. At a time where restaurants have trouble filling their staff in low tip shifts, the salaries are closer to what the employer can pay without serious risk.

Your employer may already be getting paid by a government for you to work, but that is above your pay grade.

That's why it should be enough to provide for basic subsistence.

so it's a handout to companies. corporate welfare. probably no worse than currently - a lot of companies in the UK are subsidised via the benefits system because their employees can't afford to live off their wages.