Went through a home about 7-8 months old today where there were 1/8"-1/4" gaps in just about all of the crown molding, there is also some separation in some of the wood floor boards - is this an indication the molding a flooring wasn't properly seasoned before being installed? It's obvious the molding has shrunk/constricted as its a fairly uniform problem, not limited to one area in the house.

Not necessarily. Our home is 40yrs old and the crown swells/shrinks every year with changes in moisture.

You can climatize material prior to install but there will still be changes in humidity that will cause wood movement. Climatizing helps to lessen that movement.

We moved into a new house in 2012, the amount of popping for at least a year and a half was disconcerting. Also occasional cracks at drywall seams. We are in Austin on some clayey soils. Things have settled down.