R502.6 Bearing. The ends of each joist, beam or girder shall
have not less than 1.5 inches (38 mm) of bearing on wood or
metal and not less than 3 inches (76 mm) on masonry or concrete
except where supported on a 1-inch-by-4-inch (25.4 mm
by 102 mm) ribbon strip and nailed to the adjacent stud or by
the use of approved joist hangers.
Lack of joist hangers is a big one given the improper support of only one inch. Visqueen vapor barrier needs taped and should extend up the stemwall at least 18". Given there are no straps on truss connections, gable end bracing would be a good idea.