Hitler didn't want a world war.
True - he wanted a succession of smaller wars so he could consolidate and rebuild between them.
In fact I am a tiny bit surprised that Churchill did not accept his offer of peace in 1940.
I'm not. Churchill was well aware the offer of peace was a lie. Hitler had already broken a number of agreements he'd signed. The most famous example was the peace agreement between Germany and the USSR (in which both leaders were lying and each intended to attack the other) but there were others earlier and Churchill knew that.
But anyway, once an all out war happened then Germany was going to lose. The war awoke the American industrial machine which Hitler massively underestimated. Germany was in fact nowhere near an atomic bomb. Somewhat unlike Hitler, this was an area they were only half-heatedly interested in. The general feeling is that his opinion of the atomic bomb was the same as the UK's, that it was plausible but it demanded too many resources in both materials and manpower to achieve - it was a long-term project. Their heavy water based reactor was a joke. Had Churchill known how primitive it was they doubtless would have paid less attention to destroying Norwegian assets. I guess he couldn't take that risk. But no bones here even if the reactor they had created was tiny. They had no way to manufacture materials for a uranium bomb and not a clue about a plutonium bomb. It would have required a huge leap in knowledge and absolutely massive investment that Germany simply didn't have. Few countries did at the time.
But, as you guessed, the Allies didn't know that Germany didn't have that capability. All they knew was that an atomic bomb was theoretically possible and that Germany had a nuclear weapons program. So ruining that program as much as possible was a good idea. Incidentally, the first attack on the "Norwegian assets" you refer to was carried out by Norwegians.