I would never choose this spell because NPCs generally don't make Charisma checks.
I've been DM for a lot of games, and played in a lot more, and the thing this spell tries to do just doesn't happen. NPCs are generally trying to persuade/deceive/intimidate against the player's agency, not making charisma checks themselves. Think about some of the examples you mention in the question. Merchant is haggling over the value of an item: does the merchant roll deception for its value, or does the player roll Insight or Persuasion or Deception or Intimidation? In most scenarios, it is the players that do the rolling, because it is the players that are here to play the game. Having the NPC rolling for the Persuasion check can take away form the player's agency:
Player: I think the shopkeep is lying about where he got this sword.
DM: Well, he rolled a natural 20 in deception, so yes you do.
Having the NPCs making the Charisma checks just doesn't work well with player agency. So to answer your question, "is this a well designed spell?", no it is not. It fails to consider how the game is actually played. It might work as a minor set piece that an NPC might use against the player characters, but NPCs do not themselves make enough charisma checks for this to ever be a viable choice of spell for a player character. At best, all this spell does is have a chance it giving people hiccups with no mechanical consequences. It doesn't matter if it is a cantrip or a levelled spell, the design just isn't a choice players would ever make, unless they are really into making people have the hiccups.
As a final note, you mentioned possibly using this spell against other player characters. I would be very careful with this, PVP is best engaged in when it has been agreed upon beforehand. Surprise PVP can be not fun and quickly lead to hurt feelings. But when everyone has bought into the possibility of PVP, it can be great.