You can stream from the PC to the Quest via cable or WLAN... I recommend WLAN so you are much more flexible... The advantage of the cable is (depending on the cable and performance) simultaneous charging. In my opinion, it is especially recommended for racing games where you are sitting stationary... Digitec has corresponding cables on sale... Don't buy the completely overpriced original cable!

No, but the PC must (or should?) be connected to the LAN cable. But the glasses can then be streamed via WLAN.