Yes, you have to pay for gaming on PS3 and PS4 networks, unless you have the game on a disc.
no you dont
You need a PSN account to use multiplayer features. You also need PlayStation+ (PS+) on a PS4.
They will have PSN like the ps3
Your PSN account profile should work across any Sony device that uses PSN.
No, PSN is free and there is no indication that is going to change.
As long as you use the same PSN account on the new one.
If you can't sign onto your PS4 using your PSN account that you have used previously on your PS3, you may need to change the PW. You could be entering it incorrectly. You can visit the PSN website and request a new PW.
The PS3 will not be able to play the PS4. They both are on the Playstation Network (PSN) and Playstation Plus will work for both of them as it does for the PS Vita and PS3
Because it is superior to psn.
It will download onto the console in the name of the psn account you bought it with. So if you log out of the PSN account you downloaded it with. You wouldn't be able to use the game.
No you can not get a PS4 if you trade in your game Ghost. In order to get the PS4 game system you will have to pay.
not at all. 19.99 is 19.99, save a cent.
No the Playstation Network (PSN) is Free. There is no PS3 Live. "Live" is what Xbox 360 calls it's online network and it does have a charge unlike the PSN.