While I appreciate the time and research put into this, I don't think Jesus is the slave. He's the Master, consistently throughout the Gospels. He's also Lord of Lords and King of Kings. His days of ministering to men are over and we now have the Holy Spirit as our counsellor and comforter (paraklete).
The faithful and discreet slave is a slave of Christ (Christian) who is faithfully and wisely administering to the spiritual needs of fellow Christians. Luke's parallel description of the faithful and wise servant has Jesus go on to elaborate that he's looking for a servant who'd be girded and ready to open when he knocks on the door. Therefore Jesus can't be the faithful and wise/discreet slave/servant.