Britain would try to stretch their resources through the logistical nightmare of Persia to try to contest the Caucasus to Germany or a rump Soviet proxy. If they can do it or not depends on how Germany defeats the USSR.
The USA might join if Germany declares war on them because the American Congress was unwilling to declare war and, should Germany avoid the declaration of war after Pearl, public opinion (and reality) might force the USA to focus in the Pacific.
And yet they've plundered the rest of Europe to the bone, making extensive use, for instance, of Czech and French industries and material. Raw materials can be obtained through slave labor in occupied territories or as payments required by the hypothetical peace treaty.
I also don't know which comparable allied WWII design you're comparing the Me-262 with. The allies didn't field any jet fighter during WWII and the design which came close was slower, carried lighter weapons and lacked features like a swept wing. The Me-262 suffered from unreliable engines, due the lack of metals which can be obtained through a peace deal with the USSR. On top, Meteors and Me-262 would be unlikely to engage in combat against each other except over Northwestern France, due range constraints. And the introduction of numerous, reliable, jet interceptors is certainly going to cause bigger casualties to the USAAF. Throw in more fighters and AAA overall, since they aren't needed in the Eastern Front and, should the USA go to war, they will be facing increased casualties.
Or he would have ordered the Luftwaffe to increase production of bombers believing a stronger Blitz can bring Britain to the negotiating table. It doesn't improve the number of fighters, but it doesn't demobilize the economy either.
Or he might think the Battle of the Atlantic isn't that critical now that the USSR has been defeated and try to avoid confrontation with the USA. Britain would never sit to negotiate if the USA is also at war, but it might if she stands alone.
We can think about Hitler's declaration of war IOTL as the grievous mistake of a madman. Or we might think it as a calculated gamble which might have payed off with a Japanese declaration of war against the USSR and allows the Kriegsmarine free reign to hunt American shipping while the Wehrmacht finishes off the USSR, since the USA wouldn't be ready to attack Germany in force until after the timeframe in which Hitler wrongly believed he could subdue the USSR.
Actually the US public was very much in favor of seeing Germany defeated; the question was always how much it should become involved in the war to see that accomplished. By 1941 the US was engaged in a quasi war in the Atlantic with Germany, escorting British convoys, and bankrolling its war effort. Hitler recognized this and in his mind decided to simplify the situation. If he hadn't increased conflict in the Atlantic would lead to an eventual declaration from one side or the other; especially as America would now be at war with one of Germany's allies, and Germany with one of America's.
You're correct that Germany plundered labor and industry from occupied nations (Though what it could gain was hampered by chronic coal shortages) but fail to miss the point I was making; that what it could gain from the Soviet Union would bring it no great boon. As I stated above, Germany steel production increases were mainly domestic in nature, albeit amplified by foreign output. Thus its steel, fuel, and coal industries remain just as vulnerable to Allied bombing.
You have a rather confused understanding about both the history of the Me-262, its problems, its performance, and the Allied bombing effort. Firstly delays in production and deployment had as much to do with the decision in 1942 to focus production on old models of fighter aircraft rather than adjusting factories for a number of newer models. This was further hampered by competition and factionalism within the Luftwaffe and German industry, along with Hitler's obstinacy in demanding the aircraft be deployed as a fighter-bomber, a problem that will only be amplified by his victory in the East. Technical problems in the aircraft had their basis in design problems that occurred long before the war and continued throughout it, though poor materials did cause problems later in the war. Its actual performance during the war is questionable (Achieving good kill rates in a few engagements, yet failing to perform as a magical war winner), and it will inevitably be hampered by problems in pilot training, and lack of fuel as the oil campaign gets underway. If it does somehow end up being deployed in significant numbers, Allied designs will be deployed in turn to counter it; the Shooting Star was a superior aircraft, well rounded, and had the range for escort and air superiority missions.
Germany's economic strategy from 1940-1941 was not merely to, as you say, "increase production of bombers"; it was an intense campaign of manpower and production management designed to prepare the army for war with the Soviet Union while preventing major economic disruption; in effect it was a campaign of rationalization and organization, as opposed to attempting to maximize production. Thus investments of steel and expansion of the labor force was only enough to meet expanded demand for a short war. This shouldn't be confused with meaning that Germany was under mobilized; indeed, by 1943 it was fully relying on new foreign workers to support itself. But the amount of resources and labor invested into army and Luftwaffe armaments were far less than what they should have been. This all ties together with Hitler's insistence upon maintaining good conditions on the home front, which he was only willing to cut when the nation was already in crisis. This occurred after Moscow in winter 41-42 and in summer 1944 when, previously resistant to actual implementing total war measures (A desperate gasp that kept Germany going for another 8 months), he suddenly shifted in attitude following the July 20th plot and fully approved them. With Germany victorious over its primary foe it's entirely likely that Hitler will step off Heer armament production and, rather than as you claim redirect it to the Luftwaffe (Unlikely given the clearly divided spheres of power between Milch and Speer), utilize it for domestic concerns.
Finally, you misunderstand Hitler and Nazi Germany's mentality in regards to the United States and Britain. Firstly, the economic purpose of the war with the Soviet Union was to acquire food, living space, etc to allow Germany to compete on a global scale with its principle rivals. The U-Boat war was an important part of this by allowing Germany to strangle Britain's economy and then overcome it. Hitler disregarded the US and didn't believe it to be a major threat; indeed, the declaration of war on the US was a decision to bring the war into the open. It allowed Germany to carry out unrestricted submarine war freely on a scale Hitler believed could be supported by its continental empire, and forced the US to fight a two front war which Hitler believed it could not win (And soon expected to only be fighting a single front war himself). There are very clear historical reasons for these events.
My main sources are
Strategy for Defeat, Kershaw's
Fateful Choices/
The End, and a couple of Overy's books.
Wages of Destruction was also used, though with proper fact checking. Internet research also proved useful.
