Enjoy prison (probably not the first time you've heard that huh?).
The prison segment was a little tricky for me, because it never really clearly told you when you could go retrieve the rest of your teammates, and I ended up losing a boss fight over and over and over, when I should have gone to get my back-up.
Fuck. My party is in Stornway at the Inn. I got jumpy after talking with Greygnarl and zoomed out of Upover before fetching him the booze. I'm fucked, right?
No you're fine. At one point you can leave the prison, and zoom back to Stornway. However you have to do it in the middle of climactic moment and it just seems bizarrely innappropriate to leave all the action and go to Stornway to get them. That's why I was so confused.
DQ9: Is the online component critical to this game? My new router/ modem from the phone company doesn't work with DS or Wii (also has no ethernet out, so I can't use a more configurable device in between).
It's not critical at all. There are fun cameos from past Dragon Quest characters and you can get some rare equipment from the online store, but none of it is necessary.
Yeah you can go the entire game without going online. Everything offered in the store can be found somewhere in the world or during some quest. You get the opportunity to access it earlier if you can afford it. And as fun as seeing other characaters from other games is, there's really no major benefit to it. They'll give you a piece of armor that'll make you look like them, but I don't recall it ever being great stuff stat-wise.
The search for the hero is what I consider Chapter 3 of a four chapter game (not counting the post-completion content which would be Chapter 5). You're more than halfway through, but I think it's safe to say you have a good 20 to 30 hours to go before you beat the game.