I mean if you actually read it, basically every point you made except transfiguration is addressed in the conversation Harry has with a goblin at Gringott's. And transfiguration is addressed later in the book, it's actually a really crucial plot point. Long story short, no, you can't just summon more without the philosopher's stone, which is exceedingly rare.

The angle taken, that from currency to time turners the setting is poorly constructed, is valid. Incidentally, HPMOR Harry suffers due to his "I'm so much smarter than everyone" hubris multiple times throughout the story. Once the story really gets going, Yudkowsky doesn't really shy away from pointing out when Harry's absolutist rationalism comes across as childish, impractical, or straight up unethical.