The Jew-loving Nazis of Scenario 1 seem like a pretty big departure from the Nazis we know and love, but yes, if the Germans had got the bomb things would have worked out differently.

I don't buy Scenario 2. The loss of Britain would have made bombing Germany difficult, not impossible. Worst-case scenario is that they have to develop a long-range bomber. More likely they'd have invaded some part of Europe or North Africa (most likely Britain itself) as a first order of business upon entering the war -- I doubt they would have made it to 1945 without a well-defended slice of Europe. Of course this scenario probably also has a non-negligible Luftwaffe defending German cities in 1945 but, heck, the nukes have gotta get through eventually.

I'm not sure your second scenario is as quickly solvable as you think. The loss of the uk would have been the loss of an important strategic platform - essentially allowing a second front to squeeze Germany from when it came to attack. Also it would have given Germany pretty consolidated control of our side of the North Atlantic, supply routes would have been severely disrupted.

I think ultimatelythe war would have been won but redeploying to, say, North Afric would have taken a while.

It's more interesting to look at alternative histories for World War I, in my opinion. Because the parties involved weren't as clearly `good' or `evil'.

the thing is though, WWI was mostly static trench warfare. There wasn't much that could "go" differently.

I guess the US could have never joined

Actually people tend to really overestimate how important trenches were to the stalemate. Sure, it took a lot of effort to break through a trench line but both sides were perfectly capable of doing it when they could devote enough resources. The problem was that railroads meant that the mobility of the defenders was always much greater than the mobility of the attackers and telegraphs meant that the abilty of the defenders to coordinate was much greater than the ability of the attackers to coordinate. The internal combustion engine and radio changed this when WWII rolled around.

There were also very many places where things could have turned out differently. For instance, if the Germans had stuck to the original Schlieffen plan and managed to outflank the allies they might very well have captured Paris right at the start.

Do you mistake the western front for the whole war?

Interesting would have been: Germany, instead of planning of going after France first, Russia later--goes for Russia only and just defends against France. After defeating Russia (let's assume), they try to make peace in the west.