No, I stated financial power, not economic power. Rapidly growing economies require capital, and I believe the US was still a net debtor in 1914 (or at a minimum, had better things to spend money on), whereas Britain and France were longest established and mature economies, with very substantial financial reserves i.e. financial power
And the UK national debt stands at 30% of GDP at the beginning of the 20th century and the US is also a net debtor but actually has much lower government expenditures. I am not sure what distinction you are trying to make between financial and economic power. The source of financing for growth and investment in the very mature US economy pre WW1 was US citizens savings and production. You seem to be confusing the idea of cash in hand being equal to economic potential. Its not because all the states on entering the war immediately start to issue debt to finance the war.
The UK goes from spending 8.1% of GDP on government spending in 1913 to a peak of 37% in 16 and 17. Germany from 9.8% to 50%+ in 1916 (59% in 16) the French from 10% to the high 40s. All had a large amount of slack for military spending in their economies. The US has a government spending of a larger economy that any of these with a higher per capital GDP rate of under 2% rising to 16% of GDP.
However all of that ignores this, Your basic contention is that while Germany can continue a war indefinitely the British reach economic collapse in 1916 without the US being involved.
Germany has (1913) a GDP of 244 bn USD @1990 levels.
The British Empire alone ( excluding the French) has a total GDP output of around 540bn. even exc the colonies (low GDP per head but lots of heads) its around 300bn. The US exc dependencies is 511b with a higher GDP/Capita than any of the Europeans.
So as I said, If the British and French have significant economic slack compared to Germany at all points, The price of using that is debt. Its really just a question of who you owe it to.
Printing money only has an effect if those who accept the fiat currency (domestic or otherwise) can provide/produce the goods required. Britain had no domestic oil fields, needed to import 60% of its calories and did not have the shipping available to transport sufficient war supplies from territories further away who would accept such a fiat currency. It's not just the fact Germany chose a loose monetary policy, it was the fact Germany was also relatively self sufficient, when compared to Britain, which remained dependent on global trade.
However the British Empire of 30% of the whole world, and Sterling zone has very significant oil fields, Caribbean, Burma, the Middle East, all of it then in production not to mention most of world rubber supply and large reserves of aluminium, . Its actually 70% of calories but that ignores the repatriation of calorie production - so UK grains go from 4.2mT in 1939 to 5.2, 5.9, 7.1, 7.7. in each following year, potatoes from 4.3 to 5.3, 6.7 8mT+ which in term of cargo space is 2mT freed up in year 1. And around 25% of total calorie intake is sugar. UK shipping arrivals do fall from 13,000 pa in 39 - 6-8k on the other hand just about every category of UK domestic production rises annually through the war. Primarily because the coastal trade is heavily curtailed on the east coast. US oil imports for example are a consequence of Lend Lease without that the imports would have come from another source and without the US being the source convoy patterns would have differed.
But at no point, except for a few months after the fall of France after do things get particularly serious. While there are issues of rerouting and delay these are unanticipated problems that were solved and problems because they were unanticipated.
Germany was in no way self sufficient, its was dependent on oil and grain imports from outside, and having to give away whole battleships just to get them. and on slave and forced labour for production and did not have access to critical materials at all.
But in terms of German mistakes, they planned for non of this. They entered the war with no plan to defeat France in a single campaign, no expectation of Italian involvement, a dependency on the USSR for foodstuffs and oil and in general no strategy as to how to win.
No, the British OTL had to open their books to the US to prove they had pawned everything of value as a pre-requisite for lend-lease, which does essentially illustrate the British would have been unable to fight any more.
No it indicates that they would not have been able to buy goods in the US for dollars. And you are incorrect the determining factor in the US supply - according to Morgenthau was the 1940 US election in November and then inauguration, prior to that it was all aid short of war. The US position according to US documents was not british impoverishment and 'opening the books' they had known of this since May 40. The British Planning assumed in part that the US would enter the war eventually but the spend was on the basis that it would not and cash and carry would continue therefore had to be limited to affordable critical issues. And there would always be a USD income.
As outlined above, lend-lease was only available after the British had proven (to the satisfaction of the US) Britain was already broke.
No not according to the US of UK contemporary sources.
The French did the heavy lifting in the first world war, while the soviets did the heavy lifting in the second - while the US resourced both. The British battled bravely in both, but those were scarcely a one-on-one cage fights.
Well the French did the heavy lifting in 1914-17 ( And Russians) but after 17 the lead is by the British. In terms of WW2 yes its the USSR, if you ignore anything to do with aircraft, or that around 40% and normally the best 40% of German mobile formations fought in the west. Your original point was that Britain was not well suited to fighting a war on the Continent, well fighting the main army of a major power is a bad idea even if you win so something to be avoided. But in terms of not well suited, that's another issue.
Incidentally you keep repeating assertions, not evidencing them.