A:AnswerEverything that happens on your portal happens live on your PS5, so yes. The catch would be if your wifi network band is congested, then you may get some latency. New product and some things may be addressable in future updates.
A:AnswerSony recommends 15MB down. Which isn't too much but stability I find it more important than up/down. I wouldn't trust Hotel internet but mileage may vary. Probably better off using your phone as a hotspot.
A:AnswerYou can either use the new Sony proprietary headphones being released specifically for the portal or old fashioned plug in variety, but unfortunately not Bluetooth.