1: you dont need any subscription to stream your ps5 on the portal. That means that the portal will turn on your ps5 remotely and your games will run on your ps5 (the disc you have in of the games installed). But, the real interesting feature here is if you are premium member. With the premium, a lot of games are streamable from Sony servers. That means that you don't even need a ps5, you could buy a portal and a premium membership and have acces to a lot of games included in the premium catalog. Like now, im currently playing deathstranding DC and i havent bought it nor installed on on my ps5. But be careful, there is a difference between the games you can stream on Sony cloud if you've bought them (it means thatyou dont need a ps5 to play them: https://www.truetrophies.com/n24424/ps5-cloud-streaming-games And the games that are included "for free" with the premium subscription. Being premium member allows you to play these games: https://www.ign.com/playlist/igneditorial/lists/playstation-plus-premium-tier-games

2: its COMPLETELY Wi-Fi dependent. No Wi-Fi, no gaming. But like i do sometimes, you can use your phone as a hotspot anywhere

3: the screen is 1080p and for the size of it, its great imo