I may be able to answer a bit of your question, but keep in mind this is just "hearsay" from things I've read in the past on this board.
1. Some schools, like Colorado State for example, publish how important completing pre-requisites are. They assign 10% weight of the total app to having completed their pre-reqs, so the more classes completed, the closer to 10% an applicant earns. This is one of the few MOTs I've seen that specifies this level of detail, however.
2. Anatomy is a core class. Most MOTS start out with an anatomy class, so my feeling is whether subjectively or objectively, proven success in this particular class may be weighted more heavily than an English or fine art class, for example. Don't quote me on that, but that's my impression.
3. Since you've already taken anatomy and were less than satisfied with the grade, there's no way to "hide" that class on an application. It is "counted." The best scenario is to mitigate it with a re-take (which you are planning) but I would think a higher grade earned would speak volumes above a "to be re-taken" generality. Keep in mind each individual MOT handles retaken courses differently: some average the 2 grades together, some take the higher grade, some don't look at it at all if it's after the Bachelor's has been completed, and some don't publish what their policy is. Best to call/email and ask.
I am in the same boat currently evaluating if it'd be worthwhile to re-take stat class (b-).
Hope some of this was helpful!