More basic questions ...

More basic questions the manual doesn't answer, that cause me to find this game to be unplayable right now because I cannot figure out the UI let alone try to intuit the game play concepts.  

• I evidently moved my only remaining unit (an army) in the city.... now it seems to have disappeared?   Where is it?  How do I get it back?
• Is it possible to scale the UI elements for those of us with older eyes, or who maybe play on HDTVs that are farther away?
• I clicked to train peasants, about the only thing that there is, and waited several turns, but nothing appears to have happened.  Why?
• Why is zooming back in so unreliable?  I know my mouse works, since it works in all other contexts, but in the game, scrolling to zoom in only sometimes causes the game to respond.