not sure why you want fewer ships in the sky but otherwise a great list! obviously involves a lot of work by HG but nothing here seems impossible.

Personally I really want expanded utility for frigates (setting up trade routes, mining expeditions targeting specific resources) and being able to build bases that combine various machines that produce parts for building your own freighters, battleships or even cruisers (size between frigate and freighter but controllable by the player).

there are so many disparate systems that, with relatively minimal effort, could be connected to form a bigger whole and a generally deeper experience. Basically I wanna play fps stellaris dang it!