No. These are not numbers physicists just pulled out of their asses. You act like the mathematical model could have been anything else. That's not just wrong, but decidedly anti-science.
We can test your theory: if the entire purpose of the mathematical model was to "add up neatly", and that's the reason why charge(proton) / charge(electron) is a nice round -1, then that should be true for other properties, right? What is mass(proton) / mass(electron)? It's 1836.1526734... Is that nice and neat? No, it's not. And yet physicists didn't decide to adjust their theory because that number offended them, as you suggest. Turns out you're spreading anti-science disinformation for absolutely no reason.
The purpose of the theory is to describe reality. In the case of charge, it is reality that adds up "neatly".
No, these are models with simple, testable properties. You can't wave away the fundamental charges as something somebody made up to make the models nice, conspiracy theories don't work when there is a simply observable truth.
Yes they are just that, models, which is what I said. We need X to describe Y therefore we don’t need to pretend X is a miracle because it was always designed to describe Y. It was deduced from Y for this purpose.
No idea what you’re getting at with that conspiracy theory comment, or rather I do and think you need to touch grass and stop projecting some boogey man onto people for stating an objective fact. These are predictive models not divine truth and if you think this is a conspiracy theory you either havent studied much math yourself or your are seriously brainwashed. This is not a fringe view and is a core debate within the philosophy of mathematics with no definitive answer.
With the minute difference that we do not have experimental validation for Angels dancing on a pinhead whereas there is a massive amount of experimental validation for the standard model.
Its still purely theoretical, but a lot of work has already been done to show experimental evidence of angels. I think we're pretty close to confirming their existence.