Most of this is nonsense. So long as the government is dependant on DUP support, it cannot carry through any legislation that the DUP opposes. The only way to escape that would be a General Election, and that can only happen if there is a significant Tory backbench revolt.

"If the UK is one country then there should be one set of laws for all from the Isles of Scilly up to the Shetlands, from East Anglia to County Fermanagh." The suggestion that it would be conceivable for any Westminster government to renege on devolution, and resume a power to legislate for the whole of the UK on all matters is totally unrealistic, even if there was any possibility of getting a parliamentary majority for it. The It would almost certainly lead to escalating trouble not merely in Northern Ireland, but also very probably in Scotland and Wales, very likely to take violent forms.