PSO questions (1 Viewer)

With the Xbox release of Phantasy Star Online coming up soon, I have a few questions that I'm hoping someone here can help me with.
I have a group of friends, and the four of us have been playing online games together for years. Basically almost all have been PC games like StarCraft, AOE, EQ, and Diablo 1 & 2. Slowly over the last year, we've all gotten Xboxes, and we all have Live. We enjoyed Ghost Recon quite a bit, but the other Live games leave a lot to be desired for us. I'm hoping that PSO will give us something to enjoy, but I don't know much about the game, and haven't been able to glean much info from the Xbox site or OXM. So, what I need to know is . . .
1) Is PSO a persistent world type game like EQ or AC?
2) How easy will it be to hook up with my 3 friends to play this game. That is, are there different servers like EQ, and how do you go about creating a party with your friends?
3) When you and your party are playing, do you have to interact with other players, or just NPC's in the game? The reason I ask is, we don't really enjoy playing with people we don't know, and since we are all in the Dallas area, we don't use the Xbox Live communicator, we just use the phone, and a conference call.
4) Does PSO follow a storyline that we can complete in a set amount of time, or is it just open ended like EQ?
Those are all the questions I can think of at the moment, though I'm sure I'll have more. Anyway, thanks in advance for any light you can shed on this for me.

Glenn

Thanks Jeff, that clears it up. Sounds like just what we're looking for.
We don't use the headsets, because we all have 2nd lines or call waiting or both. Plus, we're all old (mid to late 30's), and married, so the phone isn't exactly ringing off the hook.
Like I said, we've played online PC games for years, always with all of us on the phone, and we got real spoiled by the voice quality. Although the voice on Live isn't terrible, and it didn't bother me that much, my friends HATED it.
Anyway, thanks for taking the time to respond.

Glenn