I really appreciate this detailed feedback! This kind of perspective is valuable, especially since I'm sometimes too close to the story to see how certain elements might come across. (since I know exactly what will happen

)
Since I'm in community management mode today, let me address some of these points:
1 - You're right that MC, even on the Dom path, isn't the typical alpha male trope. That's intentional - he's still fundamentally a shy accountant. The Dom path is about his growth into that role rather than instantly becoming someone else.
2 - Regarding satisfaction - the walls of text in certain scenes were meant to show that MC has no trouble giving Ayumi (or Ari) orgasms. Ayumi is meant to be a tease regardless of path because that's core to her personality. She's more of a gentle dom in the femdom route and more bratty on the submissive route.
3 - Terrace was always designed as an outlier with his attributes. If anything, the remake makes MC way more standard-sized compared to the original. Part of the story's challenge (and fun!) is balancing that dynamic while maintaining a wholesome relationship. Another way of looking at it is: if you can destroy a relationship because of a larger dick, it's because it wasn't the right relationship from the start.
4 - Not every man in this universe has the same physical attributes as Terrace. Without revealing too much, Act 2 might surprise players with how things unfold.
5 - The hot past kink often focuses on memorable experiences, which naturally includes big cock encounters. Ayumi understands this is MC's kink and plays with it accordingly.
6 - The aftercare conversation following this scene addresses some of these concerns and that might not be immediately obvious.
It's still a story about discovery though - I simply decided to setup some story beats to make the build-up more believable in the limited time frame of the in-game timeline. If anything, and it might surprise you, Ayumi is actually the most innocent character in all of this. It's a
Ayumi training story 
(and you can 'train' her to be dominant or submissive)
Even if the game doesn't hit all the right notes for you this is still very cool feedback. Thanks.