I don't understand this, BTC2 coins backed by BTC 1:1 according to who? Who's guaranteeing this? Roger? Jihan? Who?

You can't compare it to USDT neither, USDT is 1:1 USD because Tether Corp/Bitfinex guarantees it. It is a centralized company. As a company they said that they have the actual USD to back Tether up.

Who's behind BTC2? Do they have the BTC to back BTC2 up?