btw, is this new expansion worth it? Considering it's just "part 1" should I just wait until it's complete? Also should I finish the main game before playing it (assuming I'm going to) or it doesn't really matter?
It doesn't really matter. It doesn't really feel like a "Part 1". If it wasn't for a vague mention in the ending voiceover, it wouldn't have felt like a "Part 1" at all.
Obviously we don't quite know how Part 1 and 2 content will connect, and feasibly they
could add sidequests to the Part 1 areas through Part 2, but as it is right now it felt really self-contained.
The expansion has very low-feeling stakes. You're helping a small fishing village to boost its economy by braving a dungeon to turn on a forge. I enjoyed it, but a lot of people complain that it didn't really feel tied into the main story or like it had an "epic" narrative of its own.
I like the new companions well enough, but one doesn't get a companion quest at all, and the other's companion quest is one of the shorter and more simple ones.
It's more Pillars, basically. A new town and a couple surrounding areas, new sidequests, and a new large dungeon that is pretty satisfying as far as large Pillars dungeons go. For hardcore types there's a new dragon to fight and a level 14 siege quest, but I poked at those and realized I just don't have the stuff for it. Whether that's "worth it" is up to the individual, I can definitely see people answering "no", but it was for me.