Answer to Question 1
A psychological contract is an employee's perception of his or her exchange relationships with an organization: outcomes the organization has promised to provide, and contributions he or she is obligated to make. The determinants of psychological contracts are direct communication from coworkers and supervisors, observations of what actually transpires in the organization, and written documents.
Answer to Question 2
Perceptions can be influenced by the perceiver's schemas, motivational states, and moods. A schema is an abstract knowledge structure that allows information about a given target to be organized and interpreted. Schemas are based on experience and knowledge, and in Bob's case, his military experience may cause him to see the workplace as a battlefield with enemies and campaigns.
Motivational states are the perceiver's needs, values, and desires at the time of their perception and can influence subjective decisions. Bob's high rating of those employees he likes suggests his motivational state may be influencing those decisions.
Mood, how a perceiver feels at the time of perception, can also influence how the perceiver views the target. A worker in a positive mood is more likely to see coworkers in a positive light than when in a negative mood. Bob's perceptions of his workers as saints and bums seem to be dependent on Bob's mood.