1. I want to ask how it is now optimized rendering?
2. Are excluded from rendering the areas behind the camera?
3. Is the display area is truncated to the camera view angle (frustum culling)
4. Are the obscured area of the player are rendered?

2 & 3. Yes, using frustum culling.

There are no other forms of culling (unless you count back face ) that I'm aware of in EE. Hopefully soon, we'll see hardware instancing and maybe in the future some sort of occulsion culling.