Russia just accruing huge swathes of powerful and highly ambitious allies in Asia against the British aren't they?
<Snipped quote by Lady Lascivious>
To be honest, I had worries about that last part, and it was my absolute limit or close to it.
As for the British willingness to cede that much control to Egypt, well, it helps that Egypt already had the land the British allowed them to keep. The British and the Ottomans were prepared to drive them off said land, but concessions were made to have the British betray the Ottomans and deal with Egypt as a (subordinate) partner instead.
I'm sure that the Wikipedia page for Muhammad Ali of Egypt said that he already controlled the territory he claimed and was about to overrun the Ottomans themselves.
@Lady Lascivious I would suggest that, as mentioned before, Japan was swept by a particularly virulent plague that left Japanese society prone to rebellion. With so many people dead, it could justify women getting a more prominent role in society in 19th century Japan.
I honestly think a Japanese female peasant is more realistic than Britain just going “Sure Egypt, you can have this insanely vital trade route, go crazy! No way this could possibly go wrong!”