We have over 1000 BTC at the moment.
It will only be confirmed that the ITO has succeeded after Bittrex's 48 hour buy-back period has finished.
Is it a one-way street? What if I go for a refund and decide I want back in because I am perhaps Bi-Polar? Will sell wall still be there?
The ITO ends when it ends. If you want to buy BLOCK after the fact, you'll be counting on the open market.