Hi, my respond may sound a little harsh, but my first reaction to your post was ‘What’s the problem?’ She told you that your draft was fine - it was accepted by the journal with corrections. And that sounds more than fine to me... That is basically the standard review procedure. Even if you had some of the things corrected before submitting, you would still have to correct other stuff...
Also, how do you know that your supervisor hadn't checked your drafts? It might appear to you that a couple of hours is not enough to thoroughly read through a script, and it's probably true. But skimming through it for crude mistakes is possible in that time and might be enough when the draft IS actually fine. Maybe you're underestimating your skills here? Also, why should your supervisor let you correct some minor stuff and let you do more of the same work again after the reviews? You could call your supervisor’s approach work efficient…
Regarding the reference letter: Again, it is your assumption that she will spend on it not more than 10 minutes. Might be not true. But even if, in the end her name on the reference letter and its general tone will count more than elaborated formulations.
Just my view on the things…