Great article! However, I don't think it is for us common folk to determine whether ICOs are legal or not, that is for the legislative and/or executive branches of U.S. government to determine. You did state that ICOs are "unclassified", so you are off the hook. Furthermore, you do make a pretty good case for why they will be made illegal and I personally am surprised they are not already.
Probably, the newness of ICOs caught legal eagles with their pants down. However, the IRS is ever vigilant and is already going after Coinbase for their customer's identities and financial information.
One way that may bring down ICOs is if a politician gets stung by Bitcoin or some altcoin and decides to go on a crusade to outlaw cryptocurrencies. But, it would have to happen soon because the rising tide of crypto is getting too gigantic and complicated to do anything about it.