What if the allies had developed the nuke in ww1 and nuked germany?

What is questions of this type are a waste of time. Einstein, had not completer the work required to develop nuclear weapons at that time. Even if they had been available I doubt they would have been use in Europe.

The German jet planes would have shot down the allied aeroplane struggling to deliver the bomb.

The war would have ended shortly afterwards, Germany would eventually have been allowed to have nukes, probably in 1926 when they joined the League of Nations (old UN). Germany may have used nukes against Russia but would probably have received a retaliation. Japan would also have nukes, being an ally of Britain in the First World War, which might have been used against China (China would never have been allowed nukes).

no chance.