Sorry, I've not RTWT, so I'm sure others have made the following points before and probably better. Apologies.
And Sorry for the long, long post.

Above and beyond cheap and easy access to food and meds, facilitated through being part of a large trading block, I think the worrying thing about no deal is the loss of access to systems such as Galileo global navigation satellite system, Schengen Information System (Member States share information to help policing across the continent) and the knock-on effect to counter-terrorism that that will have, and the negative effects to joint scientific research, for example. There are so many areas going out without a deal will have an impact on.
If we leave without any deal, we lose continuity of trade relations with the 72 countries that have trade deals in place with the EU. Our sovereignty is weakened not strengthened, as pooling aspects of a country’s sovereign power within a larger block, such as the EU, allows it to achieve national objectives that they could not realise alone, such as working towards climate change strategy, or lobbying a third state to back down from a point of conflict.
It's very sad but it's done, and we've left, but no deal is foolhardy and short-sighted. What really bothers me now is the way our Government has negotiated in bad faith. Europe is not our enemy, and the UK border in Ireland is an issue for them as much as for us because they have to protect Eire's interests. Johnson (& Cummings) negotiated in bad faith, and it doesn't play well on the world stage if we renege on treaties.
*"Scottish nationalism, atm, is even more bizarre. Leave the Uk and then transfer sovereignty to the EU."
- 'Wanting to remain shackled to a London government that treats you with contempt is bizarre.'*
I am sympathetic to Scotland. The Union campaign, and the Tory Government lied when they said the only definite way Scotland could stay in the EU was to remain part of the UK, and in less than a year they broke this promise. However, as a Londoner, I always feel it's unfair - and inaccurate, to refer to the Government as 'a London Government'. London voted to remain, and is majority Labour voting, so for the last 5 years has been subject to Tory-Leaver rule. Westminster is not London, and vice-versa. I would not blame Scotland for voting to leave the union, and envy them for having the opportunity.