Pressure requirements / PSI for water pipes can be anything they can find?

Gas lines can be made from plastic?

Newspaper for insulation is acceptable?

Roof joists can be extended to 96 inches on center?

2x2s can be substituted for 2x4s and 2x6 joists

Headers above windows and doors can be omitted?

Ceiling and floor runners are optional as well as door jams.

Horizontal fire breaks in walls are up to the builders discretion?

AC outlet junction boxes are optional?

AC light switches / junction boxes are optional?

Fixtures that attach to the ceiling can be directly fastened to dry wall using nails?

Roof rafters are optional?