1) Where I will be able to store the insulin (have yet to determine this) where will you be staying? A lot of Kenya has electricity, fridges etc. Remember that insulin can stay out the fridge for a month (especially if you use a frio or something similar in hot temperatures)
2) Access to healthcare (which there is a hospital nearby which has outpatient diabetic clinics)The public hospitals in most of Africa are no go places for decent medicine but there will be various private and international clinics around the bigger towns and cities, especially in more tourist areas
3) Access to medication as I am only able to go over with limited volume of insulin (I have therefore emailed the hospital in Nairobi to determine what type of insulin they dispense there and whether they accept international prescriptions) You should be able to get a local prescription with no problem
4) Health insurance (of which I have already looked into) Vital!
5) Vaccinations (already looked into and organising) When I went to west Africa I needed 6 different inoculations! Don't forget yellow fever and don't forget about malaria tablets, some of which need time to get into the system before you go and cost a lot of money plus you also need a reliable supply for when you are over there
Whilst you may see Kenya as a third world country it also has some very first world affluent areas so I'm sure you won't have too many problems accessing healthcare