There are many definitions of poverty. One is the Orshansky poverty thresholds, which the US uses. It's based on the amount needed for basic food and housing. Under this definition, some 15% of Americans live in poverty.
Focusing on just the food issue, people who are 'food secure' have enough food for an active, healthy life. Food insecurity is another indicator of poverty. About 10-15% of Americans are food insecure some time during the year.
A third definition of poverty, more common in the EU, is measured as a percentage of the median income, usually 40-70%. HPI-2, used for high-income OECD countries, uses "population below income poverty line (50% of median adjusted household disposable income)." Under that definition, 17.0% of the people in the US are poor.
What you are saying is that none of these definitions are correct, or even relevant.
I strongly disagree, and propose that you have little idea of what you're talking about.
Your #1 assumes that SNAP (what used to be called food stamps) is enough to bring people out of poverty and food insecurity. This is incorrect. SNAP averages less than $1.40 per person per meal in 2014. While it's possible to survive at this level, it is difficult. See http://www.jneb.org/webfiles/images/journals/jneb/45_6_Leung... for one study ("Supplemental Nutrition Assistance Program participation was not associated with improved household food security over 3 months (P=.25)")
Your #2 highlights part of the issue. We spend money on military, law enforcement, and prisons, and not on social services. That we spend the money doesn't mean poverty is a lie - it can also mean that we don't care as much about poor people.
Your #3 is also beside the point. This is an aspect of income inequality. Rockefeller, Ford, and Mellon were rich even during the Great Depression. The Empire State Building was built during the Depression. That doesn't mean that the Hoovervilles of that era were a lie. The Gini coefficient is a rough measure of income inequality, and it's higher now than it's ever been.
Your #4 has some merit. To start with, life expectancy in the US is 79.8, not 80+. Only 1/4 of Americans will get an inheritance, and the median inheritance for that 25% is $60K or so. Your logic doesn't apply to the other 75%, which is quite the majority. (I won't be getting any inheritance from my parents - they don't have the money.)
But it's true - if we changed our culture drastically, then fewer people would be food insecure or housing insecure. Accounts of life 100 years ago have families of 5 in a one bedroom place, and may include relatives. Zoning laws often prevent mother-in-law apartments/granny flats, or guest cottages, and prevent multiple families from sharing the same home.
Still, the fact that culture could change doesn't mean that no one is currently poor, which is your thesis.
Your observations instead point out that we could reduce poverty if we are willing to tax the rich, reduce military spending, shift police/prison money over to social services, and change zoning laws to support denser living.
Which are the same points everyone's talked about since the War on Poverty began in the 1960s, or since the social reforms around the Great Depression, or the socialist movement starting in the 1800s.