your assumptions are incorrect. That is not an Ethiopian machine. The green roundel is very visible which suggest it is a Libyan example.

Can anyone identify this MiG-21 that appears to have suffered
some damage while being loaded into the heavy lift freighter?

The photographer scribbled merely a few words in brief on the field
beneath which his photo is posted, saying it was originally destined
for Egypt, But I doubt of his talk about it being an Egyptian machine, supporting my assumption suspecting it to be an Ethiopian machine.
as it can be readily differentiated by carrying two bort numbers on the frame.

In all probablity, This very one should have never reached in Ethiopia
for some reason, then simply grounded in the open for a long-length of time.

Due to the EPLF’s victory over Nadew Command during the war against the Dergue.

who told you the word Nadew stood only for a military command?

So who is the horse? The Ethiopian military, third party intelligence, the mercenaries themselves? And when did you receive this information?

It is actually horses!

What can you comment us on the flight profile of the EtAF Su-27’s pilots?, from what aircraft they went?, how many hours did they fly? where did they trained?.

Recently, they have started sending them straight from L-39 but most of the pilots flew MIG-23s (some of those trained initially did flew MIG-21s but the type was withdrawn from service in 2001).

From what I heard, they fly 2-3 times a week and they do have major exercises periodically.

The training is divided into two: Aircraft qualification and mission ready. Some pilots are sent abroad and rest are trained locally.