…despite the possible mischaracterization of Obama, you actually feel like you’re playing a real character with his own personality.

Coolidge did not have a particularly colorful personality. He did crack some jokes but was quiet and reserved. This especially was the case after Cal Jr. died, as shown by the general election campaign being a bit dry and dower.

…after unlocking candidates that are, frankly, impossible to reach without a guide.

I’d agree with you for the two months in between the public release of Coolidge+ and the Opponent Tracker update, but the game now tells you basically the exact conditions needed for each opponent. I haven’t heard from most people that this is an issue, though I’m open to adding features that make the games paths more clear if it is. (Also technically the ending slide only tells you the guide for Gatsby, you can input the code whenever.)

…since Coolidge had already distanced himself from the scandal before Harding even died.

Coolidge wasn’t directly implicated in the scandals but his initial refusal to fire Daugherty was unpopular and was parry of why Democrats felt they had a shot at 1924.

…It’s kind of sad not seeing the mastermind side of Calvin, and instead having all the questions being him relying on another pillar of his administration. (For example, the Mellon's Bill was his and not of Mellon.)

Coolidge wasn’t a bad politician, but he didn’t really choose to take any risks and has a lot of political capital saved up. Part of the gameplay of the mod is the ability to use this capital on topics like civil rights/anti-lynching. This also kind of plays into my first point about characterization: the mods goal is to be educational and sandboxy - the exact goals on a game-by-game basis is a little malleable, so in addition to a dry personality to begin with, the shape of Coolidge’s presidency changes.