The ICO's problem is that if the company succeeds in bringing a real floating island off the coast of French Polynesia, there is really no way to be sure this will happen, and because the price The long-term value of the Varyon token is entirely dependent on this, so it's clear that this is a very risky venture.
Correct. Like every other ICO there is the risk that the company won't follow through.
Blue Frontiers is holding a majority of varyon in reserves. They have the largest stake in making this happen so they are incentivized to make it happen.
Most ICOs try to get all of the money up front with the promise that they'll get around to building what they promised (as they drive around in their lambos). The small upfront raise of varyon ensures that Blue Frontiers will do everything it can to ensure that the value of the varyon holds in the long term.