"To have" in the interrogative and negative forms

1) "I have a pen."

2) "I have my good reasons for that."

3) "I have to go there."

I'm often in doubt about how to put in the interrogative and negative forms the verb "to have".

The easiest case is when "to have" is used as an auxiliary verb: "I have (I've) gone to Paris" > "Have you gone to P.?", "I have not (haven't) gone to P."

1) In the first sentence, "to have" means "to possess".
I would say "I have a pen" or "I have (I've) got a pen", but only "Have you got a pen?" and "I haven't got a pen".
As far as I know, "Have you a pen?" and "I have not (haven't) a pen", with no "got" after, would be grammatically correct, but are scarcely ever used, at least nowadays; and "Do you have a pen?", "I don't have a pen" are rather American constructions (are they used in England, too? Because I'm interested in British English usage.)

2) In the second sentence, the meaning of "to have" can hardly be described as "to possess": is it still possible to say "I've got my..., Have you got your...?, I haven't got any..., good reasons"?
Other similar examples: "He has a beautiful voice", "She had blue eyes", "I have a temperature", "We have a right to know", "I have a good opinion of Sandy".

3) In the third sentence, "to have to" means "must, to be obliged to". I think that I should say "I don't have to go there" and "Do you have to go there?": am I right? Perhaps also with "got"?

I'm a little bit confused. Would you help me to bring order into the chaos of my mind?

Thank you very much for your answers.