why is the backstop so important to the deal when it is not needed for no deal
Well you have hit the nail on the head, I have seen today that representatives from at least 5 EU countries ( Netherlands, and France included and maybe Germany ) have been speaking to Boris and his colleagues about changing the treaty that Theresa May signed up to ). I am horrified but not surprised when Selmayr and Barnier now say that no deal was never put on the table by May.... seems like May either did not understand negotiating, or deliberately bought a deal back on purpose that she knew would not get through parliament - because she never wanted to leave EU.
I see Andrew Marr interviewed the Irish deputy prime minister today and insisted that the backstop would not be changed and the backstop was imperitive to the agreement.
Later in the interview he said in th case of a no deal
And he was followed by IDS who poo-pooed all he said. IDS seems to be living in a fantasy world. There's going to be a lot of humble pie eaten in the coming weeks.