If you're legally married, the 'Conjugal partnership of gains' should apply.
My wife and I bought a house and land about six years ago, and my name is on all the titles as '. . . spouse of . . .'
If my wife dies first, then I inherit her half.
I believe that this is the only way that a non-Filipino can legally own land in the RP.
Always worth a read: BOOK I (FULL TEXT) : CIVIL CODE OF THE PHILIPPINES : CHAN ROBLES VIRTUAL LAW LIBRARY
I'm not allowed to post URLs, so you'll have to do a search.
With regard to 'unscrupulous wives': That can happen in any country. Do your research before you make any commitments. Check, and check again!
With regard to becoming a Filipino citizen: You have to file a case in court to start the application process. A neighbour of mine has just spent two years, and countless Pesos, to become a Filipino citizen. He was successful, but now he has to endure a two year probation period before it is finalised.