Wang Wei's reaction to the Heaven Opening Emperor has everything to do with trust. He can trust his ancestors to some extent after analyzing their deeds, interacting, and his wife's personal experience with them. Nevertheless, he would never completely trust them since the number of people he trusts completely can be counted on one hand.
As for the Heaven Opening Emperor, he is in the category of people Wang Wei can "trust" once he is on the same level as them, with no overwhelming power disparity. Once that happens, he has no trouble reuniting the Wang Clan for his benefit.
He looked in the distance before disappearing and returning home. He first went to check on Li Jun and the others. He did show them the memories of what happened in the Science and Technology World since he did not want them to be affected by the taboo.
Join my Discord to have many discussions about the story and so on. Here is the Link: https://discord.gg/bnsezTApeY