There was no prospect of the French Navy defeating the RN at the Nile.
No chance of the territories of the Ottoman Empire being considered a higher priority than Ireland.
No 'internal issues' that could convince any plausible British administration to abandon efforts against France.
Napoleon had neither the intent nor the ability to establish Egypt as a French colony. Anything less than bringing the Ottoman Empire to terms meant the French effort was doomed to defeat.
Nor would the Protestant extremists joining forces with the Catholics under any circumstances.
The constant harassment of British supply lines is nonsense...
Mumphy, to be blunt, your first timeline went way into ASB territory even without your clinging to a ridiculous Hessian role with absolutely no basis in reality.
Well, this is meant to be entertainment, but I will deal with your issues each at a time.
The Hessian thing is ASB, but I simply thought it would be pretty cool.
There was a definite prospect of the French defeating the British at the Nile. If the French hadn't chained their ships together, they would have been more than ready to face a British attack. Remember that the French are at the dock, where there will undoubtedly be cannon. All it takes is the battle occurring during the day, and the battle could have been a French victory.
It isn't the territories of the Ottomans per se the British are worried about. French success in Egypt and against the Ottomans is a definite threat to Britain's possessions in India. And we would go through hell or high water to hold onto India, whereas in Ireland we have less to lose.
So, serious outbreaks of violent action in Britain, no matter how bad, would not have caused Britain to back-down even slightly in France through sheer bloody mindedness? Now that is ASB. But the British will probably just play a smaller role.
Napoleon in OTL won many battles in Egypt, but the naval battles cut off support from home. He worked to make the lives of the Egyptians easier and if he had focussed a little less on uncovering the Pyramids, and more on war, he could have won.
You forget that in the age of revolutions, many people we would consider odd allied with one another to fight a common oppressor. The Orangists and the Catholics have allied purely to push out the British. The UI was more secular. In my next update, the fragile alliance in the north will fall apart.
Last of all, my name is Mumby. Not Mumphy.