There is no such thing as a favorable brexit deal. Britain is already in the most favorable position possible with regards to EU relations: they have all of the benefits of EU membership, but with a special deal that means they're exempted from some of the membership dues, and they can have their own immigration policy and their own money. Britain has a more beneficial position in the EU than any other country in the world, in or out.
There is absolutely no way that the EU is going to let them leave and keep most of the benefits of membership. The hardliners want to get everything and give nothing, and surprise surprise, the EU wasn't going to let them have everything in exchange for nothing, so the hardliners hate it, and everybody else hates it because it was a stupid idea in the first place.
It would be similar to half the republicans and half the democrats agreeing on a key policy & fundamentally disagreeing with the other half of their respective parties.
(it's actually even worse than that because there are at least 3 main positions [hard exit, soft exit, no exit] which divide the two main parties, meaning nothing really has a clear majority).
The way the UK government works is: from the majority party a government of ministers is formed from their group of MPs. By convention individual MPs in this government (called front-benchers) have a cohesive support for the overall government policy (if they disagree with the policy or vote against it then by convention they have to resign). Anyone from the ruling party NOT on the front-bench can (and often will) vote against the government.
Brexit has been insanely divisive. Internally, the ruling Convservative party have at least 4 different positions, including the official government one. Many front-benchers have resigned.
Fundamentally the problem is this; people voted for Brexit. But only just. So really nearly half the population doesn't want it. It was simple to answer a simple yes/no question. But exiting is a hugely complex question whereby it is nearly impossible to negotiate a compromise that works for everyone.
Oh well, you live and learn.
Because "Prime Minister" is not the head of state, so there's little respect for the position. Her position is equivalent to Speaker of The House in the US, only in a system where The House is also the Executive.
I believe members of the UK armed forces would probably dispute that.
https://en.wikipedia.org/wiki/Oath_of_Allegiance_(United_Kin...
Dan Carlin has a series on his podcast discussing the background of the war in Asia in 1937-1945 (https://www.dancarlin.com/product/hardcore-history-62-supern...). One of his major points about the Japanese government at the time was that the military held allegiance to the emperor, who couldn't or didn't actually do anything, rather than the civilian government. As a result, the military could do essentially anything it wanted.
That didn't end well.