Is the husband's saying to his wife: "Good morning of submission and obedience to you, my queen," considered minor shirk, given that he means she is his queen and his only princess after his mother?

Saying "morning of submission and obedience to you" is not considered shirk (polytheism), as what is meant is the submission and obedience befitting a creature. For obedience is due to Allah, the Messenger, and those in authority, as Allah Almighty said: "O you who have believed, obey Allah and obey the Messenger and those in authority among you." As for khudu' (submission) in language, it means humility and lowliness, and it occurs between one creature and another, as Allah Almighty said: "And lower to them the wing of humility out of mercy."