A: This depends on your license. A single-user commercial license typically allows installation on two computers (e.g., a desktop and a laptop) but with the restriction that you cannot use the license simultaneously on both. For multiple concurrent users, you would need a network license or multiple individual licenses.
The installer automatically detects SketchUp 2018. Confirm the path. vray 3.6 for sketchup 2018 google drive
At this point, V-Ray is installed but will run in . You have a few options: A: This depends on your license