On errors: Yes, this is the main point I agree with. Fortunately most languages have frameworks with do this now. The main thing I would wish for would be a more configurable 'warning' or 'notice' level wich would indicate e.g. type coercion or addition of strings or other nonsense when debugging.
On typography: seems like a lot of trouble for no substantial gain.
On Input Methods: People know `x - y` is left to right. `x = y` is easy enough. These points take a couple minutes to memorize each.
I am intrigued by nested quotes, however. In some languages such as Chinese they use arrow quotes -《》 - which would be easily nested and visually distinguishable.