(a resource for nwn2 builders)

A good place to start with general animations is the switches page here:

http://wendersnaven.com/node/43

The short answer is that you can set the following variables on a creature:

Ambient Animations
X2_L_SPAWN_USE_AMBIENT = 1

Immobile Animations
X2_L_SPAWN_USE_AMBIENT_IMMOBILE

With no waypoints, "X2_L_SPAWN_USE_AMBIENT" includes the familiar wandering around near their spawn point and doing some basic interactions with other NPCs. "X2_L_SPAWN_USE_AMBIENT_IMMOBILE" causes them to do the same interactions (waving, force talking, etc.), but they stay in one place. They will turn to face other NPCs, however.

There are a few waypoints that cause additional behaviors. From x0_i0_amins:

Creatures will move randomly between objects in their
area that have the tag "NW_STOP". (I think there is a % chance of them doing this or the standard wander around.)

UPDATE:  After some testing, it appears the behavior in the next two paragraphs does not work. Generally speaking, waypoints across areas don't work at all in NWN2. They tended to be inconsistent in NWN1, also. Begin incorrect documentation:

 Creatures who are spawned in an area with the "NW_HOME" tag
 will mark that area as their home, leave during the day,
 and return at night.
 
 Creatures who are spawned in an outdoor area (for instance,
 in city streets) will go inside areas that have one of the
 interior waypoints (NW_TAVERN, NW_SHOP), if those areas
 are connected by an unlocked door. They will come back out
 as well.

End incorrect documentation. 

There is a good conversation about ambient animations scripts happening here:

http://nwcitadel.forgottenrealmsweave.org/showthread.php?t=1184