Further consideration of plastering/tiling issues.

With respect to the bathrooms: There are no tiles (except on the floor) on the second floor east side bathroom in this house. On the second floor west side bathroom, the ceiling and floor of the shower stall are tiled, as are the walls where tiling extends from floor to ceiling. The rod for a shower curtain has been fastened with screws apparently inserted into holes drilled into the tiles. The tiling on the walls of that bathroom extends 48 inches from the floor. The bathtub in that bathroom has neither enclosure nor curtain. It is fitted into the corner created by the south wall of the shower stall. The tiling around the bathtub is 32 inches high, with an upper edge of the same height (50 inches from the floor) as tiling on the other walls. A single towel bar has apparently been glued to the tiles above the bathtub. 

The three bathrooms in the Addition have no shower stalls. The upper edge of the bathtub enclosure tiles are 64 inches above the upper edge of the bathtub. The upper walls and ceiling of the bathtub enclosure are plastered.  There is a waterproof light fixture in the ceiling of the bathtub enclosure.  Shower curtains are suspended from spring-loaded tension rods above the outer edges of the tubs.  The periphery of these bathrooms is tiled to 48 inches above the floor.

Each of the five bathrooms in the house has a recessed medicine cabinet above the sink. These cabinets have an inside depth of 4" and project 2" into the room.

THIS IS IMPORTANT:

A. Before applying drywall or Durock, one must make provision for any desired recessed i) medicine cabinets, ii) toilet paper dispensers, or iii) soap dishes.

B. If one mounts 1/4" thick tiles on 1/2" thick Durock, one must anticipate an hypothetical challenge by the electrical inspector for building 3/4" deep sheathing with electric boxes designed and placed for a 1/2" deep enclosure. Arguably the circumstance that neither ceramic tiles nor cement will burn might make such construction acceptable, - but perhaps only from a licensed electrician. Inspectors are unpredictable.

C. One must anticipate the problems created by attaching to walls that have been tiled, towel bars, mirrors, medicine cabinets, wall-mounted and floor-mounted cabinets and shelves. 

In consideration of all this, and in order to prevent further delay, WHAT I WOULD DO is:
A. I would accept the absence of recessed cabinets and fixtures.
B. I would instruct Mr. Barros to line tub enclosures and shower stalls as well as lower, potentially to be tiled sections of bathroom walls with Durock, and to line all other areas including closets and all ceilings with drywall.
C. I would instruct Mr. Barros to put the usual skim coat of plaster on ALL Durock and drywall in the bathrooms.
D. Unless you have made provisions (of which I am unaware) for access panels to the  metal chimney and ventpipes. I would instruct Mr. Barros to finish the closet in the 2nd floor south east room, and the ceiling above, as is.
E. I believe all issues of tiling can and should be deferred until the spiral stairs, the inside doors, floors, and finish carpentry have been installed.