Citi is offering me the Citi Select Amex card (I already have the visa signature version). The starting bonus is 25k miles. I probably plan on keeping the AA Platinum Visa for ~6 more months before closing it. Would I would be losing any future offers if I took this one. Is it possible to get them to bump up the bonus miles to comparable to a new card?

Another question I have is the card is pre-approved, if I apply will there be another credit pull?