1) Presumably the b is smaller than 0.0005, but not equal to 0. Then it will be printed as .000. The reason being that the effect of employees is such that an extra employee doesn't affect the regression very much. To see it in your table, compute a transformed variable by dividing by a sensible number.

2) for categorical variables it works the same with respect to a reference level (b is set to 0 for that level), so the odds with sector=0 is .489 of the odds with sector=1.