In Hero's Journey parlance, Maz Kanata is a threshold guardian. JJ Abrams' calling her castle a "watering hole" places that scene at the beginning of Act 2, akin to the Mos Eisley cantina scene. Big hollywood Hero's Journey script man Christopher Vogler, who's worked for Disney and whose book is a step-by-step road map for any JJ Abrams' movie, has the biggest hard-on for that "Descent into the Special World" part of the journey that he calls the watering hole where the heroes learn about the rules and backstory of the Special World.

Following their escape from Jakku, they're going to Maz's castle to interact with a bunch of thugs, pirates, and just anybody who's going to demonstrate the nature of the Special World in microcosm. In ANH, this is the point of the story where we see stormtroopers start to take an interest in Luke and the droids, Obi-Wan really demonstrates he's more than an old hermit, the get Han and Chewie to join their adventure, etc. This would be a good time in TFA for Han to make a tongue-in-cheek reference about shooting first.

Before Maz's castle, the movie is going to be all space ships and explosions-- all militaristic "real world" stuff. It's Maz and the watering hole setting that introduced the first concrete mention of the Force, because the Special World is a spiritual realm where the military evil turns out to also be spiritual evil, and the Light Side/Luke is the boon/elixir/goal to obtain by the end of Act 2.

Also, not to be an ass, but Han dies at the beginning of Act 3.

He's basically acting as Obi-Wan in ANH and Qui-Gon in TPM, the old warrior who guides and mentors the new heroes onto their path. In Star Wars language, the mentor has to be sacrificed in Act 3 of the first episode in order for the heroes to see the necessity of their quest and come into their own.