Who said it would be easy? The entire idea of war isn't easy.
The point was that you're giving the impression that losing Britain, a world financial and industrial center, would be a net gain for the war effort because "The Uber Empire", which was already well on its way to breaking apart from India to Africa, would be willing to follow the absolute direction of what in effect is a government in exile after years of NOT doing that, as the recall of Australian troops to defend Australia from the Japanese threat showed. Quite frankly, you make it sound ridiculous.
Why move it? Build a factory in India to make Mk1 widgets for installation on the new "Liberator" class aircraft carriers built in the fine shipyards around the empire and you're benefiting from the cheap labour.
Because, as any industrialist will tell you, consolidation is the key to efficiency. Building fleet infrastructure is a major, time consuming task that takes months to years, not weeks, and will be nowhere near what was lost in Britain. And it still doesn't change the fact that what you're envisioning would face numerous examples of domesticate opposition across the dominions. Widgets built in India are widgets that workers in Ottowa won't be making, or will be making for lower wages.
I'm also dubious about the carriers of yours as well. Britain didn't build them for the Pacific when the economics and massive industrial base of Britain, so why/how are they going to build them now? You might get a few baby flat-tops, the kind that are obsolete as soon as they're finished, but there isn't exactly much of a navy for them to be used against, and the US will almost assuredly do the heavy lifting when it comes to the invasion of Britain.
Movement difficulties? The RN owns the waves. Any nation that attempts to interfere with British shipping will be pounded to dust in short order. Remember, they don't have the difficulty of holding defence of the UK nor keeping the shipping lanes across the Atlantic open. The only navy that can threaten them vaguely is the KM and even then, only in the North Atlantic.
I'm sure the American and Japanese navies would beg to differ.
What? You said the RN owns the waves, and didn't give any qualifiers. This isn't exactly pre-WW1, after all.
There's also the problem of commerce raiding by a German navy that won't be bottled up in, well, Germany. Germany doesn't have to destroy shipping now, it just has to keep the invasion fleet away. That's a different situation.
Or what? The US will hold it's breath? The Empire doesn't need Lend-Lease to hold an island in the North Atlantic anymore, so they have nothing to lean with there. The US isn't going to fight a war with the Empire to prevent them from building more ships.
No, but the Imperious Uberous does need guns, jeeps, food, bullets, guns, liberty ships, men, and warships if it wants to do the minor act of taking back Britain, all of which will be quicker AND faster (and no worse quality) to come from the US than to take the wallet-busting factors of building it themselves. And if there's one trait about the US that's been continuous across the ages, it's that it plays the "my balls, my rules" game.
Seriously. Work this out. To get across the Channel to France, with all the benefits of absolute naval and air superiority, an unsinkable aircraft carrier, a gathering and relief area, and a bit more, the US supplied most of the equipment, men, and even then there were places where Overlord could have become a blood bath, just from the weather. Retaking the British isles from across the north ATLANTIC, one of nastier seas in the world, is going to be much much harder, bordering on ASB. Were Britain to fall, liberation would almost certainly come from the direction of the continent, not North America.
The simple fact is that the Dominions would have no problem ponying up cash for that kind of fleet. The simple fact is that both Australia and Canada easily had the resources for large military commitments, but simply did not generate the political will to "fight to the last dollar".
I call bull. The British empire was nearly bankrupted by the cash-and-carry policies of the pre-lend lease, and there is way you can convince me without supplying concrete facts, data, or interviews, that LOSING a world financial and industrial center of the world is going to increase revenue flow?
Australia was already moving towards the US, which was/is better suited to protecting it from threats north in Asia. Canada is already inside Fortress America, as are various Caribbean Islands. South Africa is very far from Germany, and Operation Torch showed that an African base would be much farther north. India was in it for independence, not for love of god and king and country
Look at how they handled post war debt right after both wars: Britain had their debts forgiven. As well, the propaganda of Mother England being occupied would give the Dominions the political will required.
This might be a better example if the effects on Britain weren't much more famous. Crippling British and French debts to the US after WW1, which both suspended payments of due to the economic burden. Even more economic damage after WW2.
And I also have heavy skepticism for the value of such propaganda. 9-11 motivated people to "Buy America" despite it being cheaper for about... 6 months. And this won't just be buying more expensive toys; building redundant empire-wide infrastructure when the US already has more and cheaper available is going to cost out the walzoo.