Question 1;
Will Britain leave the EU on 31st Oct, with or without a deal ?
The law until recently was that the
default action was the UK leaves the EU on 31st Oct (deal or no deal). Then Parliament brought in a new law that said Boris had to ask the EU for an extension by mid-Oct (17th?) if there was no deal by that stage. So, in theory, there will be an extension if no deal is done. But, as pointed out above, one theory is that he could
ask for a extension, ignore the reply and then the UK would leave the EU automatically on 31st Oct because it's already on the statue books.
You might as well flip a coin for answers to the other 2 questions.
FWIW, The EU parliament today had a non-binding symbolic vote that they would give the UK an extension if they asked for one.