Sorry guys, and no offense Robert, but a crack in the drywall as shown in the original pic, certainly does not require a Structural Engineer to figure out.
This is obviously a shrinkage crack that is normal with drywall construction. I see this on a regular basis and are usually corrected within the one year warranty. Sometimes these cracks necessitate installing a permenant control joint, re-taped and painted.
We are dealing with wood here and material that is installed with no enviromental evironment protection while it is being done.
Moiture intrusion on to the material, before it is all said and done could be exactly what is needed to create these cracks.
Home Inspector= Crack in the drywall, should be monitored to make sure that it is not related to movement of the structure. Any increase in size, should be evaluated by a Credintial Contractor and/or Engineer.