If you have an account prior to April 20, you can get them even if you don't own a psp yet. I downloaded on my bro's ps3 the other two psp games that I didn't get.
On the second question, that depends. For the NA store, you get Sonic 2, Streets of Rage 2 for 30 days, but Magic The Gathering: Duels of the Planeswalker is free, so you can keep it. Once your subscription is up, those games that have a time limit won't work until you resub again. So it's like a rental. Themes avatars, and dlc are yours to keep.