I can see the appeal for multiplayer, but personally I always play complex games in singleplayer where I can review all my cities buildings and worker allocation without a timer or without feeling guilty for making the other guy wait. So to me there isn't much of an upside to it. So why not have classical turns as an option, even if the game is balanced for simultaneous turns.

Alternative:

If not, than how about making ordering ship movement but having the order executed at a later time possible. Some sort of "Ghost mode" where I can split a fleet into two parts and send both parts into different starlanes without danger of the natives suddenly jumping on the second fleet when the first has left. And when I'm done, I click "execute order" and both are out of the system before the natives can react to the split.

Also giving an order in ghost mode to be executed right at the start of the next turn. For example when I´m ahead of an enemy in a starlane let me order "go to the next node and move into guard mode to intercept him". Currently the move all ships button can be used in such a fashion when clicked right at the start of the turn but only in a severely limited form. It can only make them move thus privileging escaping over catching and giving the mouse an advantage over the cat.