I think so because on the PS3 it is.
Yes, there is a PSN link on the Vita's LiveArea.
Owning a PSN account doesn't cost any money, and there are many free things on the PSN that you can take advantage of.
Yes, Angry Birds is available on PSN in a PS Vita compatible form.
The PS Vita does not have a UMD slot so it can't play those. However if you've bought a PSP game on PSN, it can possibly be downloaded on PS Vita, you'd have to check to see if it is available, you might have to wait for it to be enabled.
There's no Naruto games on the PSN store
Yes, the PS Vita can download a Skype app from the PSN.
nope - kane_215 (psn) follow me on twitter @young_ghillie
Yes under certain conditions there are totally free PS Vita games available even if they are not permanently provided. Membership in Playstation Plus can have a free trial period and they have PS Vita games that are free to play if you have a membership. They also are free except for the membership cost if you decide to purchase a membership. Also when PS Vita games are purchased from the Playstation Store some offer to allow file sharing and those games would be free for those that you shared them with. There are some free games on the PSN, such as Ecolibrium, Frobisher Says, Wake-Up Club, AR games, etc, which are free to play but some have the option to buy things for them with cash. Also PSN+ members get a certain amount of freebies during the year including full retail games. But these can only be played as long as you're a PSN+ member.
If you connect your ps vita to your router wirelessly then it is free
Only the 2nd gen PSVita slim has internal memory, 1GB.
Skype can be downloaded from the PSVita's PSN store, from the 'Social' tab.
The only ones you can play are the ones on the PSN.