The reason they don’t want you using your own WiFi access point is probably because dorms are prone to over congestion if everyone sets up their own WiFi network.
If you wanted to fuck with them-and you don’t mind spending money-then you could set up your WiFi and get internet via mobile carrier or starlink, so that you never actually have to agree to their terms. Then when/if someone comes around to bitch at you you can watch them slowly come to the conclusion that they’ve got nothing on you.
Otherwise your options are to follow the rules to the letter and live without vr streaming, or accept that you might get in trouble. Some WiFi routers can be configured to not advertise their network; annoying because you’ll have to manually enter the network information on every device, but it might keep you from getting caught.
As for connecting multiple devices without paying; there’s probably some creative ways to tunnel all your traffic through a single device to get around that. Could still get you in trouble if you’re caught.
If you’re doing anything that could get you in trouble with the school make sure you save the email in which they told you using your own router is allowed.