>>296999813
This is a general problem using SteamVR via Oculus, rather than just vrc. I've found that, generally, avoiding to use both the Oculus and SteamVR overlay will reduce the chances of getting super bad lag. That said, sometimes it just happens and the only way to solve it is to get out of VR and restart the Oculus runtime service. 
The tearing (like a water effect) is both SteamVR and Oculus trying to do motion smoothing at the same time - Try turning off the SteamVR motion smoothing.