Yes, not a great as Unity but it’s still pretty good especially after they switched to Vulkan over OpenGL. VR performance still could use some work though.
Yes, PBR materials are fully supported. Actually one of the earlier things in 3D that was implemented, and then imoroved
Yes, now I don’t know if HAVOK has a Godot plugin but there is a Jolt physics plugin that’s designed to be plug-and-play, with a few exceptions (it doesn’t suppory soft bodies afaik)