It's interesting, however one small point.
The idea of having a king seems reasonable- after all the revolution was against foreign kings rather than kings in general unlike the French revolution. However, I doubt that the Congress would sign over many of its powers to one man, even if he were George Washington. Especially, they wouldn't want a hereditary monarchy, but most likely one elected either by popular vote (which wouldn't be a case at the time as the popular vote for president was only introduced i nthe 19th century) or by the Senate.
So, I'm not opposed to a stronger American executive, even if that executive takes the title king, it's just that it seems most likely the Senate would vote George (or someone else) King for life adn then when he died elect someone else. There may even be term limits, although I don't see how that would be any different.
So, if you're goign with a stronger executive, fine. Just the whole 'King' thing loses its weight when you consider how emasculated the office would be.