A thing I forgot to mention is Russia gained the warm water port of Nagasaki in exchange for their military aid. It was not out of the kindness of their hearts, but access to not only a warm water port - but a very well positioned one at that, enabling power projection of the Russian empire into the south pacific. 

However, I think the standards of plausibility are nevertheless being applied very unevenly in this, with regard to the central premise of the British Empire voluntarily ceding control of Egypt, the Levant, and a Suez Canal. Not to mention the liklihood of revolt by the traditionalists and conservatives within egypt that would have been furious with Ali for ceding what he did. He would be lucky to retain the support of his army and thus retaining his throne. 

Yes, my alt is certainly unlikely. But more unlikely than the British voluntarily handing over all of that to Egypt, and Egypt not suffering massive internal strife as a result of Ali's concessions? I somewhat doubt it. Yeah, it's unlikely - but honestly, to me, it seemed perfectly reasonable by the standards of the central premise put forth.