What exactly can I do with these tokens?
Can I buy them for Bitcoins?
Do I understand correctly that the sale will last a month?
Of course you can buy tokens for Bitcoin, as a rule any project it allows besides purchase in Ethereum. Into the account of date you are almost right, tokens will be on sale up to 15 May inclusive, there was a week.
remained only one week, until the completion of sales, and I'm wondering whether there is now any bonus interest on the purchase. Or I will not have time to buy tokens with a bonus?