According to current
linguistic theory, the
rules of language are determined by what is used. So, a sentence is
gramatically correct if a
real person would say it.
As for word usage, the
OSPD gets its words from real dictionaries.
Modern dictionaries get their words from real literature (a practice started by the OED). So, real people use these words. You may not. In fact, you probably don't. Because you're not a
Hebrew scholar, you don't need
qoph, or
sheqel. If you're not a hacker, you're unlikely to use the word
blit. That doesn't mean it's not a word.