A:AnswerI think there are one or two titles that are cross buy, but for the most part all quest games exist in their own ecosystem.
There is an official update coming that will allow you to hook up your quest to your PC and run PCVR games that way. That is assuming your PC is strong enough to run all that.
You can also sideload mobile VR games onto your quest but I do not know how that works. From what I've seen it isn't difficult to do.
Hope that helps.
A:AnswerYou have to set up an Oculus account. I’m pretty sure that you can use a PC or iPad and you may even be able to use the browser inside the unit but I didn’t try that.
A:AnswerNo, it is not... however with the Oculus Go or Quest no PC is needed at all, they are both independent systems. If you get the Oculus Rift or Rift S you need a VR capable PC to run the games.
The Oculus Go is more centered around watching videos and content where the Quest is the much better stand alone gaming device.
If you are wanting to access the PlayStation VR library the only option is the Playstation VR... just beware that you also need the Playstation Camera and Move Controllers with that choice.
A:AnswerThere are at least 50 to 60 games and apps and they keep updating constantly ... Everyone that I show it to wants one ! Much better that the PSVR ! Get it! :)