Odd FPS in Editor & Built game.

So yeah. I'm having rather annoying problem here. No matter what the settings are, the FPS wont change a bit in the game.

Here is the Statistics of the scene.

The FPS always stays around 30-80 when looking in different parts of the scene. I can lower the Pixel Light Count to 1, lower the textures to "Eight Res", and the FPS is unaffected, it wont get better or worse. The scene is optimized heavily, there is LOD in most complex meshes and most static objects have been combined to one mesh to reduce drawcalls. [Before Optimization the FPS on scene was 15-30 WITHOUT any effects and shadows] Plus Occlusion Culling of course.

Now i do have an slight idea or suggestion that may be causing this, but i cannot confirm it because i'm not sure if Unity works this way.

All 3000-4000 models in the scene come from one FBX, that has the whole scene built up ready. My idea was originally that does Unity need to load this FBX every time when it loads up model that is inside of it? The FBX file is around 70mb. And if it does, is it safe to delete the FBX without compromising the scene itself? I have all the same meshes in the project as invidual FBX's without childs.

I have GTX 1070 Strix, Intel i3 3,5Ghz and 8GB of RAM. We also tried the same scene with my friends PC which has same GPU but Intel i7 and 16GB of ram.. Same problem, FPS wont change no matter how low the settings of game are.

We cant possibly release an game that struggles with GPU like GTX 1070. And on top of that, the game looks good but not "Crysis" looking good so the FPS problem is huge question mark.

Help would be great!