Since its near you, have you tried going there and explaining it to the manager?
However while the restaurant's manager might care, as I understand it her husband is the hard core chef who ensured it's a success, why should he give a shit? Presumably the errors are just in the text for stupid barbarians like me - many of them don't even order from his real menu anyway. His taste is what matters, nobody comes to the restaurant because of the typography or web site design, they come to eat his food.
Additionally, I have it in my head that not bothering to fix menus shows a certain admirable pragmatism. "Frind pok" is not correct but it is correct enough.
The last one is a problem because real family restaurants do want to raise prices/be more upscale too, but none of their customers will let them because they expect banh mi to be $3.