General Questions: Sandbox space-simulation

Hi, my name is Dave.

Me and a small Team are creating a sandbox space-simulator in Top-Down-View. We have experience in programming, but not much with Unity itself. Therefore we could use some help with some main features of the game.

First a few things about our Game and problems the we have:

The Player controls a single Crew-Member in Top-Down View and controls it directly with the Keyboard. You move inside your Ship, that is Build out of "Tiles" in Minecraft Style. Machines in the Ship consist of different Tiles with different purposes. There will be a huge variance between the Tiles, even identical Tiles will have different parameters (for example the material it consists of), so we didn't use assets and built the Ship by Inserting new GameObjects and adding Sprits, Scripts,... step by step.

Because of this layout we have not found any way to save a scene and rebuild it later. We have tried to include SQLite Databases, but the Write/Read times were horrible. It is also nearly impossible to find a good way to save an array variable containing different GameObjects and other complex things. How do you guys save a scene? Is there a better way than calling every script in every object plus a controller script for saving every object, its contents, state and variables in a bunch of save-files?

The next Thing are complex GUIs. Navigation should take place in a starmap. Until now we have found no proper way to create a GUI that is nice looking and fast acting for example when zooming in or moving a map. We found drawing even simple things can be quite difficult. We hope there is an easier way to do this than rebuilding the whole GUI every time you zoom in or out.

We also need to change the scene several times later in the game. Is it possible to run a scene in background while using an other one simultaneously or do we have to do that by saving the scene and returning to it later by loading?

You see we have many problems and there are even more to come, if anyone is interested in the project and more detailed information of what we plan to do, please contact me. We are thankful for every help we get. Thanks for your replys :)