You should never forget that you are arriving at Addis Ababa airport already at 2500 m altitude and on the most routes to central or northern Ethiopia (+ Bale mountains) you will travel at altitudes almost 3000-3500 (4000) meters. So if you descend into a valley, you will be at altitudes around 1700-2000 meters and you will have to ascend up to 3000-3500 metres again.  You will surely recognize that there is less oxygene available. So hiking may be in some parts very strenuous.
In small groups we will always pay attention to the others and adapt the speed of walking to the weakest group members. The possibility of taking part in a hiking tour is not a fact of age, but of fitness.

There is a lot of being done to improve the irrigation system and also the infrastructure. Of course there is still a great difference between rich and poor, and there is still great poverty in the big cities. But you will recognize that the Ethiopians work hard for their future. And we can support them by a sustainable way of travelling. If you want to show respect to the Ethiopians and their culture, you may try to learn a few words in their languagge, the Amharic languagge. There are many ways to learn it. The easiest way is to download some apps on your smartphone, that you will find for example in the Google Play Store (for free).

On your journey there will be good telephone access only around the cities like Addis Ababa, Mekele, Axum, Gonder, Lalibela, etc. In areas like the Simien mountains, the Bale mountains or in the Danakil desert there may be no network available. Wireless internet is accessible only in hotels in the cities and sometimes in smaller towns. It may be useful to buy a SIM-card in Addis Ababa to get an economic telephone connection or to use Skype (if there is internet).