Some questions regarding quality and performance in Unity.

Hi

I have implemented many hight detail models, and some of them are huge. Now I am starting to see some lag in Unity, but only when I interact with the items (when I move them and things like that). It also takes a longer time to start the game in the editor. But it runs really well after it has loaded. So here are my questions.

Can I have one loading scene and at the same time start the other scene in the background (when running the game outside Unity, I am fine with the waiting time in the editor)?

Can I fix the models so they won't cause lag (in editor)?

Can I get Unity to use more of computer recources (even when it is working really much it only uses a fraction of the total recources)?

Any tips on working with many "laggy" objects in Unity, or how to optimize the performance for the game when outside Unity (so it can work on as many computers as possible). But I still want to have the option to have "Ultra" graphics for the computers that handle it.

Just so you know, my computer is really good. So that is really not the problem in this case.