That's not a problem - when the stock is liquidated he would be taxed, no - the problem is that he's taxed differently and there are mechanisms in which that tax he pays is deducted, e.g. donating much of it to an organization he controls.
Yes, but he can live on a cheap loan collateralized by his stocks and never sell - that way he pays no tax)
Any asset can be collateralized. Every homeowner in US can do the same thing with a reverse mortgage. Leveraging assets isn't tax evasion. It doesn't even qualify as avoidance.