My first question is, why do you make so many assumptions?

I'm not sure which assumptions you mean.

Next, do you expect voluntarism to just be a switch in society with an overnight shift in personal and cultural philosophies?

No. I don't have any expectation that the USA (where I live) will ever become voluntaryist at any time (barring an apocalypse), but people can move in the direction of not supporting specific policies that involve the initiation of force against peaceful people.

Do you make the assumption that the current 1% have managed to amass their wealth without doing any harm?

No. I do not make a universal claim like that. If somebody harmed others, then I would not oppose addressing those claims. I do know people with lots of money who have not harmed others (other than indirectly through their support for the government). I would not condone harming those people.

Does 'no harm' mean as long as they didn't break any laws?

Good question. No. Laws are guidelines that might point to things to think about, but slavery was once legal, so I do not simply rely on laws.

Many corporations do harm all over the world as they crush supply chains...

Now we are getting somewhere! You are pointing to specific claims about harm (one organization against another). I am vaguely familiar with antitrust laws and the logic behind them.

Our differing views on the harm related to "crushing a supply chain" are probably a key point of our differences. If there are two gas stations in town, one locally owned, and one owned by a giant corporation, and the giant corporation cuts prices below the cost and the other goes out of business, this is against the law in the USA.

I don't see the act of cutting costs an active harm against a competitor. I see the claim from the locally owned gas station as a demand to the other gas station to change its behavior to benefit the locally owned gas station. Yes, there is a correlation between the big company slashing prices and sales at the other gas station. That is how business works.

This is why I see the demand from the locally owned gas station as a demand for a positive obligation on the behalf of the big gas company: the act of changing the price on the sign at the big gas station has no physical effect. The small gas station experience a change only to the degree that fewer customer appear.
If customers go to the big gas station, that is their free choice to do so. If the little gas station goes out of business because its prices are higher, that is a consequence of the free choice of consumers. If a group of people want to get together and buy from local stores, they can do so without forcing others to do so.

I shop at a locally owned middle eastern market every week, in part to avoid Walmart. I pay more to do so, but I do it anyway.

If you want to reach out to people who are not already supporters of big government, you could try making an argument that positive obligations are a justification for using force agains peaceful people.

You haven't answered the other questions, so I'll make it easier:

Do you believe that failure to abide by positive obligations defined by other people constitue harm?

Do you believe that positive obligations defined by other people are a legitimate reasons to force peaceful people to do things against their will (e.g, pay a tax, do community service, mandatory military service... you can specify).

thx