Sure, if an IRS agent comes with a policeman, and you pickup a gun and start waving it, you may get shot. But if you just don't give money to the IRS, nobody is going to actively try to kill you. Your life gets much, much worse, but you aren't killed.
if you attempt to defend your property from their theft then you will be shot.
So yes they will actively kill you.
If anyone is stealing, in this hypothetical where you aren't paying your taxes, it's you, from the rest of us.
While there can be a case for Land taxation, there is no ethical claim for Income Taxation.
With any good or service, there is the same economic trace back to government subsidies. Your income comes from the trading of goods or services.
I own a house, if you trace back the chain of land ownership, the original title was issued by the government. (Where did the government get that land from? They stole it from the indigenous people.) When the government gave the first titleholder the land, they granted that title subject to the understanding that taxes would be paid and laws would be obeyed (including taxes and laws introduced after the original title was issued.) You can't give better title than what you have, so every subsequent owner, up to myself, has inherited the same obligation to pay taxes and obey laws. If the government's right to tax me is invalid, then my ownership of the land my house is built on is invalid too.
The scenario I described was the IRS taking your land to cover taxation based on your Income, IRS does not tax land in any way. They tax income and other transactions but not land.
The IRS however can take your home, car, or any other personal property you own to cover income based taxation.
I actually agree with your assessment for pure land taxation (not to include any structures, or other items you places upon the land)
Taxing land value I believe has a ethical foundation for the reasons you stated, taxing income has no ethical foundation for those same reasons. If you believe the government has the right to tax land because it has or once had an ownership interest over that land, then the only possible reason you could agree that the government has the right to tax income is if you believe the government has a ownership interest over your person.
Suppose someone wants to lease land, and make the rent proportional to the tenant's income. You might think it is an odd arrangement, but freedom of contract implies if landlord and tenant agree on this it is binding. Now, that essentially describes income tax. The government owns all its territory, it has leased it to the residents of that territory, it has made the rent (tax) proportional to income. If you don't pay your rent, the government can seize your moveable property, just like how your landlord can seize your moveable property if you don't pay your rent. (Unpaid rent is a debt, and its collection can be compelled through the same legal processes as any other debt.)
As I said, you are not figuratively killed in prison.
Secondly, prison does not end your day to day life. There are many people serving time who will get out and be able to go on with their life. Not everyone who goes to prison gets a life sentence. And even for those who are doing long stints, they very well do have a life worth living. Prison sucks, but saying someone who's doing a stint (or multiple) doesn't have a life worth living is a akin to telling them to commit suicide.
I understand you were probably engaging in hyperbole, but it's clear (to me at least) that you probably have not encountered many (or any) people who have gone to prison. Your view of prison inmates is probably a combination of a few tv shows. As someone who has a better view I'll say that prisoners do have lives worth living, they do have rights, and (when prison is done correctly) they should come out better on the other side.
Prison is shitty, and leaves a stigma on people that is hard to shake. But prisoner is in that situation, not of that situation.
While they may not kill you directly for paying taxes, if they come for you, or your property, and you attempt to defend yourself they will kill you
Thus I believe that is in fact being killing because you did not pay taxes and that also means you in fact you "have to" pay taxes