Questions/Observations.

I can answer a few of these since nobody else will:

1. Hade's potion was a big contrivance in the story. It's not explained how he got it or if he can produce more of it. So, anything related to it will feel contrived.

2. You apparently did miss the details. The Muses sung that because Hercules was mostly mortal therefore "...Zeus and Hera wept/Because their son could never come home". Later on, Zeus explained to Hercules that only gods can live on Mount Olympus. So, Zeus and Hera couldn't get Hercules because he was a mortal man.

3. Looking at it now, the editing was a little jumpy. Hercules was still inside Demetrius's shop and then it suddenly cuts to him being outside with Demetrius saying an audible but strained "I'm fine". It's unknown if he's still carrying the vase. Perhaps, in between the cuts, Demetrius found a place to set down the vase and close the curtain.

4. Hercules went to the Temple of Zeus to discover where he originally belonged. Zeus answered it, and told him a way to restore his divinity. After the "Zero to Hero", Hercules talks with his father in his temple about his past adventures. I naturally assume during his years of training, Hercules would find time to go to the temple and talk with Zeus about casual things.

5. Well, since Zeus can talk through the statue which requires air, whistling shouldn't be much of a problem.

6. It's never explained who created the rules for mortal men to become gods.

7. I'm not sure, but good point.

8. Young Hercules was a young teenager (probably 13) since his voice has reached puberty. Adult Hercules is actually eighteen according to the prophecy. So, obviously, by the change in his physical body, Hercules had trained with Phil for years. Naturally, your voice would stay the same once you have hit puberty. I assume the change in voice actors was meant to indicate to the audience that a measure of time had passed and he had grown up since then.

9. You do have a point there. Both have a slow buildup of music until it reaches a grand finale, but Hercules's score sounds more brass (especially the French horn, if I recall) to sound more heroic. Hunchback uses more string and wind instruments to sound more lyrical.

10. It was told for expository reasons, but Hades seemed to have reminded Meg of her past to convince her to use her "manhandling" abilities to take down Hercules.

11. The bunny and the gopher disguises Pain and Panic used in the woods barely resembled them. So, I assume they can radically change their appearances when they want to make themselves look less obvious. And as seen with the female Pegasus disguise, they can fuse together into one disguise.

12. In Hesiod's Theogony, Zeus released three cyclopes from Tartarus, which served as a prison for the Titans. The filmmakers might have adapted that into the film.

13. It's clear the Cyclops saw Hercules reach for the torch. Perhaps, the Cyclops didn't sense the torch would be much of a threat of him.

14. Since the Titans are depicted as elements of the Earth, I assume each element counteracted each other to the point they couldn't reach stability and therefore exploded.

What we do in life, echoes in eternity.

7) HERCULES's training is designed so he can learn to control his strenght... but why does he have to do push-ups and such? He's literally the strongest person in the world!