Dr. Mas,
In the case of the use of synonyms, I am ableo the give an explanation as a native German speaker: It is considered bad German to repeat words too often, hence the use of synonyms like remedy/medicine/drug etc. I do remember having to search for alternative words in School to make my essays better ! In German literature you will usually not encounter word repetitions in sentences following eachother if they can be avoided so that the text is not boring to the reader. When I read the Organon in German, I have the impression that this is what Hahnemann did. IMHO we have here not an interpretation problem, but one of writing styles.

In the case of the other words, Chris gave the explanation as I understand it too.
Claudia