Ok, I am glad the air is clear then.
The Rhys translation, according to a little Google research, is the one still preferred. I don’t know if there have been any authoritative ones since 1954.
As for my translation, well, 1354a is the very first paragraph of the entire work. It’s all I did. I suspected that knowing my friend Aristotle, he would neatly state what he intended to discuss in the very beginning. I haven’t translated beyond that point at all.
Time permitting I can do a bit more, but my skills have grown rusty in a year and a half of disuse. It just takes a bloody long time to do short passages. I shudder to think of what I would do with Plato.
As for the debate, Gadarene neatly summarized what appears to have happened. After the initial appeal to authority was rejected, you seem to have switched gears.
My answer to your above query is simple, I suppose. Aristotle simply did not study mathematics as we do today. The Hellenistic natural philosophers clearly considered mathematics a science, for it revealed to them truths about the natural world. I don’t have a text of Euclid on hand, but if I ever find one, I’ll get a cite for you. 
Likewise with medicine. The very word epistemon implies a knowing of something concrete, rather than a talent or skill. Aristotle uses the phrase eipein epistemon, which means to use specialized, scientific terminology.
So while rhetoric can be systematized, it is not a science, for it deals with no specific branch of human knowledge. As Aristotle even says, some people can succeed by practice and some people are just naturally good at it.
Aristotle does not believe the same is true about zoology or metaphysics.
MR