Great report and pictures. It brings back good memories of when I was there with my sister. The episode with the dogs sounds nerve racking.
It sounds like the Diamox is not working well for you. I guess it is hard to know without comparing the same activity with or without it. I tried to climb Kilimanjaro once but failed due to altitude sickness. I am always thinking about trying it again but using the Diamox. Did the Diamox make you nauseous?
How much did you pay for the bikes and the guide? I like to keep an eye out for cheap rentals overseas. Great that you have a good friend willing to do this with you. None of my good friends would ever do this