A free market is a market without regulation. What type of regulation and maintenance are you referring to? Do you look at the market today as a free market? Many things on the "black market" would be legal under a true free market; drugs, prostitution, ext.

Taxation is involuntary as you stated. Removing someone's property without their consent (threat of violence) is theft. If the government doesn't own anything, which it doesn't, than anything it gain it took from someone else. Since its way of obtaining those funds are done under threat of force, the government is just a power source used to force people to give up their property to a centralized power.

Yes, if a crime is committed (fraud for example), that property was obtained through theft itself, and it should be returned to the rightful owner....which would not be the government. As it owns nothing.

The argument that the "government prints the money" does not mean that the government has ownership. It simple created a monopoly on exchange of currency, forcing people to be paid and trade in its fiat currency. However, the wealth created for which the person was paid the fiat currency was created by a private individual or business. 

I believe certain ICO purchases are considered a securities issue. EOS for example.