Some questions in regard with grammar

Hi,

Please look upon the questions below and express your thoughts. Thanks beforehand.

1- Is it true that verbs in English are either Lexical or Auxiliary, based on some classification?

2- What's the rule on how to use "be" in sentences like: "But again, truth be told, if you're looking for the guilty, you only need to look into a mirror."

3- Use or usage. Yes, there're plenty of webpages talking about it. Both are nouns (use only in specific situations, of course) and with little difference. But how do you, teachers of this forum, use them? That is, where do you prefer using "usage" to "use" (noun form) and vise versa?

4- Was born is what that is used for the date of birth naturally. I've heard, "I'm born" is also grammatically correct, and I, too, would go along with that perspective, but, on the other hand I suspect it's very uncommon. What are your points of view please?

5- It's said to be a rule of thumb that we can't use "more" for those adjectives which normally have -er for the comparative form in English. There're, of course, some exceptions in this case too. What's the rule in this case? If both are possible for a number of adjectives, what are they? And in what occasion are we allowed to use "more" instead of "-er" for one, or the other way around?