The fact that there are several pop ups, such as tech completion and the occasional video that plays accompanying the techs that grant fame, that cannot be turned off or minimised makes the simultaneous turns a source of huge frustration in the early game.

Getting harass-ganked by aggressive independant nations is a cheap way that challenge is added to the early game. Preserving your retreating units can be mitigated by storing orders in retreating units and then using the 'order your units to complete moves' but there are many occasions when you need to directly path a unit using right click to move. This doesn't just apply to retreats it applies to any aggressor moving on an army stack with less units to score an easier win. Having to quickly close a bunch of pop ups while attempting to do this is a totally miserable experience and its ridiculous that I sometimes have to stop teching a technology I am one turn away from to avoid it.

Suggestions 

- make those pop ups a disable-able UI option in the menu.

- create a hotkey option for order units to complete moves that is not the same as the end turn hotkey. Right now that is the solution I use but pressing that hotkey more than once might open up a diplomatic window or move the camera away from where I wanted it

- make right click to cancel not a 'read only' hotkey. this is such a user hostile configuration