First of all, the hardware you specify is theoretically possible, but as of today no manufacturer has done it.(For very good reasons).
Second of all, those videos you posted can be rendered in real time, but it all depends on the details. Resolution? Different effects such as Depth of Field, etc? Those videos were rendered through Ray Traced graphics and with some powerful at home hardware, you could render a pretty good looking scene at a decent FPS. Not as good looking as the videos you posted.
Some real time ray tracing:
The pixar scenes that one user was talking about are rendered in a high resolution, probably 4K. However they don't take several hours per frame otherwise it would take over 100 years. You can render a complex high res scene on a modern computer in ~30 secs or less.
Unless they can get rasterized graphics to simulate light as good as ray tracing, ray tracing will eventually be implemented inside GPUs in the future. They have GPUs with 3,000 cores. If each core could perform calculations for ray tracing, you would have real time. Current GPU hardware limitations don't make that part so easy.
It looks to me like since left is your first one, that is why it is the only one working. If another one is true but left is also true, it will never get to the other ones. You will probably have to fix the logic
It will always work if you are local because your router doesn't mind distributing packets behind the private LAN. Anything outside the network will not want to work because the client will try to send a packet to the server, but the server is behind a NAT(Network address translation) and since the router didn't see the server send out a packet first, the router will just discard the client's packet and never connect. However if the server sends out a udp packet to try to connect, the router likes to switch ports so you don't know which port the packet will come out of. That's what packet forwarding is for on the router. So when the client sends a packet, it goes to a different port than expected and the router still discards it. There are solutions such as "hole punching". The easiest solution tho is to have a dedicated server outside of any NAT to handle the requests.