R. Yosef Bekhor Shor addresses each of your examples in his commentary to Exodus Chapter 20:
כבד את אביך. ואת אמך אף על פי שאמרתי לך שלא תכבד ותעבוד כי אם אותי אביך ואמך כבד
Even though I told you not to honor and serve anyone but Me, honor your father and mother.
Apparently, the concern here is that the previous four commandments focused so much on God being the only object of worship/honor that you might have thought that even honoring parents would be an infringement.
לא תרצח. שלא תאמר מאחר שאמר הקב"ה שלא אכבד כי אם אותו ושבת ואבי ואמי כל אדם שיעשה לי שלא כרצוני אכנו נפש
So that you shouldn't say that since God said that I should not honer anyone except Him, Shabbat and my father and mother, anyone that does something to me that I don't like I will strike his soul.
Apparently, the concern here is that the previous few commandments which emphasize that honor is for God, Shabbat, and parents, might make you think that regular people don't deserve any respect and you can therefore kill them on a whim.
לא תגנוב. שלא תאמר על רציחתו ועל ניאוף אשתו אני נזהר שמא אוליד ממזר ונמצאתי לתת כל יגיעי ועמלי לממזר אחד שאינו בני אבל לגנוב אותו או ממונו כדי להשתכר מותר
So that you should not say "I am warned against murdering him and adulterizing his wife lest I bear a bastard and it will turn out that I have placed all my toil and effort into one bastard that is my son. But to steal him or his money in order to profit would be permitted.
Again, it seems that the concern is that the existence of the previous commandments might make you think that something not as bad would be permitted.