I haven't tested it with win 10 but it's in the specification. I use it regularly with my iPhone and in the last 3 years there hasn't been a Samsung TV I've come across that couldn't do it. So I would be very surprised if it didn't work.
I think it depends on the distance between the seats and the TV. You should be at least 2 metres away from the TV because it is quite large at 65 inches. It doesn't have to be QLED for presentations. Whether 2 screens can be connected to the Microsoft Surface is a question about the Microsoft Surface.
Unfortunately, we do not have any more detailed information on this at the moment. However, we are making every effort to include the latest models in our range as soon as possible.
The Samsung QE65Q6FN (65", 4K, QLED, LCD) has intelligent voice control (Google Assistant, Amazon alexa, Microsoft Cortana).
It also has a QLED screen instead of LCD. And therefore better quality.
There are no other differences.