Logically-speaking, poverty can't exist without inequality. It's a condition of "want" that requires others to "have".

Practically-speaking, inequality is insidious because it enables violations of rights and unjust denial of opportunity even when poverty has been eradicated. Cold comfort, to the middle-class family of people mowed down by a rich motorist who faces negligible jail time because the money they can spend on a lawyer is outside the scope of what the legal system is built to handle.

There's poverty without inequality. In some primitive tribes everyone was poor. When natural adverse conditions hit some regions, also poverty was widespread.

That the justice can be persuaded in a certain direction with money is a weakness of the system. I don't think you would consider equal and just that every person could influence justice. The problem is the justice system.

No. Poverty is not relative to what others have. Poverty is relative to baseline needs. So poverty absolutely can exist without inequality.

Inequality has no moral characteristics. It is not "insidious." The fact that disparate effort and disparate circumstance lead to disparate outcomes is just that; a simple cold fact.

That some people use their power or wealth to take advantage of others is a moral issue. But again, this is orthogonal to disparity of outcome. Or do you claim poor people never steal from other poor people, or that rich people never steal from other rich people?

Envy is not the basis of poverty, need is.