A:AnswerYes, the headset works with other devices (e.g. PS4, PC, Mac). PS4 does not, to my knowledge, yet support 3D audio, but if some games do, they'll sound great on a pair of Pulse 3D.
The USB device makes for a much faster and more reliable experience than Bluetooth can provide (lower latency being just one benefit). So long as the USB is plugged into your device of choice, all you have to do is turn on the Pulse 3D headset and you're automatically connected and ready to go. It's very convenient IMO.
I don't believe the Pulse 3D can connect via Bluetooth, but you could connect it to your phone's headphone jack via the included 3.5mm cable.
A:AnswerMost PS5 accessories come in stock randomly. Tech support recommended me to "save" the item to be notified when it is back, however I doubt that will help. Delivery to home should be possible however in the case I had, it would have taken over 10 days LONGER to get to my house, so picking it up in store would be better if you are on a time crunch