I have one general whose icon changes from minute to minute. When I select him, he's a war elephant. When I move him into a city, he becomes a stone wall. The next turn, he's a Praetorian Cohort. Shortly afterwards, he's a peasant, or an incendiary pig, or a warband. I can never tell, and occasionally I miss him because I don't see a character picture.

As to the blackouts, I have had them happen once or twice to forts, but most of the time, they happen to a city when I complete the new government building.