The House of Hanover changed their names
The previous name of the House of Windsor was Saxe-Coburg-Gotha at that point, but it doesn't really matter. Hitler didn't think in terms of governments, but saw everything from a racial perspective. To him, the British were ethnically related to the Germans (via the Anglo-Saxons), so in his thoughts they were his natural allies.
Germany declared war on the US on December 11th 1941
Yeah, but it's a bit more complex. The USA were already quite involved into WW2 at that point ("lend and lease" and all that), and the declaration was only stating the obvious (of course Hitler also wanted to profit from the US's weakening after Pearl Harbor). Still, it's the same situation as with Britain - he didn't WANT to fight the US, not only because he had "enough on his hands right now", but there was literally nothing to gain for him in such a war.
Was it because of the Germans violating the Belgium independence, IIRC? If yes, this should explain why the French, who devoted all resources to a Metz-Mulhouse (approx) defensive line, were so shocked by the German attack.
But at least for France, there was a plan for war declaration.
... Anyone still remembers about Poland?
This.
The violation of Belgian independence was the reason for British involvement in WW1 (but they were bound by their alliances with France and Russia to go to war with the Central Powers anyway). Before WW2, both France and Britain had internationally guaranteed Poland's independence, and when Germany invaded them under false pretenses.
Of course, there also have been plans for a preemptive offensive on France. Germany always had to reckon with a French intervention on their expansion. But you always have to think of the years before the war: Germany was able to annex the Rhineland, the Saarland, the Memelland, Austria, the Sudetenland and Czechia through semi-diplomatic means and France and Britain stood there and did nothing. Hitler was seriously up to the illusion that he could continue with Poland and get away with it.
...because they didn't foresee that Germans can copy plan from IWW? Oh yeah, they did. They had 1 million troops there. However, Allies prefer to don't remember the fact because the less facts are remembered the more evil Hitler can be in minds of societies (and they are crystal pure in comparison). Anyway, it's a topic for a different thread.
The Rhine border was so heavily fortified that they knew Germany would be stupid to attack there, and the Belgians themselves were very much aware that they would serve as France's open flank again. What they weren't prepared for, though, was that Germany was going to pull the same trick on them and invade via the Netherlands, nor that modern warfare with paratroopers etc. would be able to bypass their defense lines so easily.
Still, the whole German Ardennes offensive was a huge stroke of luck for them. If their convois would have been discovered early on, they would've lost pretty much their entire army and practically the whole war on the western front.
I remember that in one of the two World Wars (not sure in which tho) the English DoWed the Germany, due to violating the Belgian independence. I also think that in WWI, Britain did nothing about it. So I assume it was the second (remember Dunkerque, IIRC there were British soldiers there)
As for Poland, yes, the German agreed w/ the Russians to invade the country and share it, I don't recall this to have provoked a great English reaction. Anyway, to DoW, you must be able to be on the offensive. Britain never did this seriously till 1943.
No, it was the other way round. When Belgium was invaded in WW2, the major powers were already at war, and nobody was all that surprised when it happened.
The Russian-German plan to share Poland was never made public (it is referred to as "secret protocol" for a reason), so Britain had nothing to act upon.
When they declared war, they were able to act very well, though. Their acting just followed the typical British stratagem: winning superiority over the seas, setting up a blockade, and waiting for its continental allies to wage the land war.
