2) If robots do replace all jobs, the "money" comes from sale of goods just the same. Half the workforce are working and doing the work of the other half - the robots produce the goods / services, and the humans lounge at home.
And just who is going to give money to the humans lounging at home with which they will pay for housing, food, clothing, transportation, goods and services? How much money will they be given? Or is this "home" you speak of just going to be a tent in Hooverville?
3) The result of the above is that food and goods become so cheap and plentiful that the concept of "buying" them will seem old hat.
The economic system is one where all goods and services have to be paid for at some level. Even subsidized services like public transportation and health care require some level of payment. Are you suggesting that the long-term unemployed will be government subsidized sufficiently to have an apartment to live in, with Internet, streaming electronic entertainment, beer in the fridge ("free as in beer") and an endless supply of junk food?
5) Who cares? If you have no job and no money but food is so cheap that going an oiling a robot once a month pays for everything - wow... perfect life.
Even if food, goods and housing are amazingly cheap, if you have no money to pay for them, then they are still too expensive for you.