Hi, first off I'd like to say that overall, GalCiv3 has been a pretty enjoyable experience. But, that said, there's one particular aspect of the user interface that I hope receives some more iteration in future patches.
If you couldn't guess from the title, that UI bit is how idle ships are handled.
As it stands, if a ship is idle and you want to end your turn, it is necessary to click the "pass" button on the ship. This sets its moves to 0, and then the ship will no longer count as idle.
While manageable for small numbers of ships, in my empire that controls half of a "huge" sized galaxy, managing every single one of my idle ships sometimes proves to be a major pain--lots and lots of clicking. Idle Ship > Pass ; Idle Ship > Pass ; Idle Ship > Pass, over and over again until I'm allowed to end my turn.
I can understand the argument for this system: in a lot of cases, it's important to always have ships doing something useful, and this UI element is in place to aid players in managing their empire.
However, a large portion of the time, I just want my ships to reach their destinations and sit there. I know you can put a ship on the "guard" command and they won't count as idle, but then in the future if I move my ships up to stand watch on my advancing influence border, I've got to tediously put them on the guard command just so I don't have to deal with clicking through a ton of idle ships at the end of each turn. There have been a lot of times where the idle ship buttons pops up and I've said "Crap, which one of these things did I forget to set to guard now?"
So, in short, I think the idle ships button does its job, but it does it in a way that intrudes upon the gameplay. I find myself fighting with the mechanic a lot.
I have a potential solution that would fix these concerns:

So I think this solution would do the job nicely, but it does need a tad bit of explaining:
>The Idle Ship button becomes a separate entity, and no longer replaces the turn button when ships are idle.
>It will only appear (Or at least be clickable) when ships are, indeed, idle.
>It will function identically to how the idle ship button normally works--it will cycle through all idle ships.
>When you click on the turn button, it will advance the turn, passing every idle ship if there are any.
>(Potentially--this issue could be handled in many ways) To notify the player that a new ship has completed construction, there could be a small little (+) icon or something denoting "hey a new ship is dun buildin" next to the idle ship button. This would help communicate to players that they have new ships on the field to give orders to, which is something very important to know. IIRC GalCiv2 gave you a pop-up every time a ship finished which could be a bit annoying, but I think this simple icon modifier would be low-key but effective.
Why would this work?
As said before, since it appears the main function of replacing the turn button with the idle ship button is to keep players aware of their ships and properly utilizing them, this new approach will still accomplish the same goal. The location of the idle ship button next to the turn button will make it very clear that players have ships that aren't doing anything, and they'll be able to individually inspect which ships are idle without being forced to manage every ship under their control.
I'm not sure if this should be expanded to other situations that would hijack the turn button: Colonies are super important to always keep managed, and there generally won't be very many of those (compared to ships) that will need your attention. Shipyards, and ideology points also make sense, especially research. Maybe shipyards would auto shut-down when construction completes and another UI notification pops up next to the turn button? I suppose at this point I'm rambling, but as a fellow game developer, my mind is always trying to find ways to streamline the user experience.
Thanks again for the awesome game, keep up the good work!