A few questions about frame rate

I'm using VRTK/SteamVR and a Vive with a 1070 card. Working on stuff for a few months now, but just purchased some cool buildings from the asset store and turned on the frame rate in the HMD. It seems reasonably ok detail wise for VR, but I saw some dips when I added too much to the scene: https://www.assetstore.unity3d.com/en/#!/content/33052 So I had a few questions about what I can do.

1. Hidden Objects Effecting Frame Rate - When you are in an interior space...

A few questions about frame rate