Answer

There is no difference between prohibitions between a person and another person and those between a person and God. That is a classification with no essential significance whatsoever. Perhaps there is a practical difference regarding the need to appease the other person as part of repentance, and even that probably does not depend on the formal classification of the prohibition. For example, regarding honoring parents, the Minchat Chinukh mentions a practical difference for repentance (whether one must appease the parents). I am not at all sure that this is really a practical difference. Even if it is between a person and God, one should still appease the parents, because the commandment is to honor them, and appeasement restores that honor to its proper place.
"Keep far from falsehood" is not a halakhic prohibition but a moral guideline, at least in the accepted halakhic interpretation. It does not appear in the law codes or in the enumerations of the commandments. According to the accepted approach, the prohibition against lying was stated only regarding testimony in a religious court.