Intrinsically, these matters are not bad. Only by Hashem restricting them do they become negative. One who fights his inclination to refrain from this type of sin is to be commended and deserves a greater reward. By looking carefully at the wording used in the seemingly conflicting proofs, one sees that the difference that I have pointed out is true. According to the above Rambam it is clearly understood.
Logic dictates to DO, and preferably, there is no drive to do otherwise.
One has to be on guard because his inclination towards transgressing these types of mitzvos should be present, as per the Toras Kohanim. One refrains only because of the Torah's command. I will repeat the section in parshas Shmini that deals with this Rambam. The Rambam himself acknowledges this reason in his Shmonoh P'rokim chapter 6. I wonder if it is possible to read the Moreh N'vuchim differently.