I forgot to answer this point earlier. In fact there is plenty of evidence that the EU was seeking to punish the UK because various EU officials have said so. There was the BBC documentary a few months back for instance where two officials were joking together that they were going to make the UK a colony.
Dominic Raab claimed that Martin Selmayr, the head of the EU civil service had said that "Northern Ireland was the price the UK would pay for Brexit."
Most revealing of all was a quote made by Michel Barnier in 2016 in the French magazine Le Point - “I’ll have done my job if, in the end, the deal is so tough on the British that they’d prefer to stay in the EU”.