^^ In how many days after ITO will the trading of Block/BTC begin?
The Block:BTC pairings will begin at the start of the ITO and will never stop.
The ITO is just a sell wall on a pairing.
So, once the ITO is sold out completely, you can start trading blocknet shares for BTC?
Yup.
This will continue at traditional exchanges until the Blocknet's tech is ready to pay fees to holders, at which point Blocknet tokens can be redeemed at the NHZ asset exchange.