Day/Night System idea.

I would enjoy day/night cycle a lot but you are right. It'd definitely be a ton of work to add that to a large scale game. Imagine muzzle fire for every single unit in the map during the night. The amount of lightning quality and the coding for it all will not only be immensly time consuming but also hardware consuming(arguably one could have an on or off option so people with weaker computers don't drop in FPS). It'd be great if they have enough time for this however, as day/night in Warcraft 3 was pretty awesome and that game is 9 years old. Imagine it on a modern game of galactic scale.

And yet I have seen many games do it. Don't assume that the dynamic lighting that you see all the AAA game engines pedal these days is the only way to put headlights on all the units.

If the intent is for ambiance and has no effect on gameplay, I don't see why the idea can't be considered. A proper lighting engine is probably going to be needed anyway, considering the different planet types that will exist. Things would look different depending on if you're standing on a regular rocky planet, in the depths of an ocean of a water planet, or in the dense gas regions of a gas giant.

And I don't mean different as in being unable to see more than 5 feet away on a water planet, or "Wrath of Khan" style fog in a gas giant. Just ambient effects that look nice when you're looking at them, but can be ignored after a while so you can get back to focusing on RTS play. An occasional partial eclipse passing over my base? Yes please!

Oh, and a side note... headlights? street lamps? Really? Giant robots from the future would probably multiplex the entire spectrum from infrared to xrays for realtime analysis. Visible light bulbs... puhlease. Thats sooo 50 centuries ago.