I'm not sure if this will help anything, but here's my two cents.
When in doubt, the rolled "R" pronounciation is certainly the preferred one since that's what it's "supposed" to sound like - the "educated" pronounciation, if you prefer. Similarly, just because many English speakers prounounce "that" as "dat", but that doesn't mean people learning English should adopt the latter it as "standard" pronounciation. Assuming that the initial "R" in Portuguese sounds like "H" is a gross generalisation.
That being said, the Wikipedia page is very well sourced and explains it quite well : http://en.wikipedia.org/wiki/Portuguese_phonology
It would be interesting if you asked your in-laws if they percieve "rei" (Portuguese) and "hey" (English) as homophones :)
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