Also,  Neither I or my other siblings want to force my unemployed brother and sister out of the house because we do not want them to be homeless.

My wife never went to college and feels inferior to her 3 siblings who are engineers and an accountant.   

Yikes, talk about your sibling rivarly.

This is what I would write:"Hi *name*, I realize you're experiencing a sub-par experience with us, I've talked it over with my co-owner siblings and we've decided that in this case we want to make a special exception for you.

Or depending on how old they are, you might find names of parents and siblings in the census info - latest public census is 1940.If someone immigrated, the immigration paperwork can be ordered or sometimes can be found in the logal courthouse, where they lived at the time of naturalization.

Just keep using the information that you find to dig deeper including siblings, children, spouses (past or present).

The trust owns the property (my mother is the beneficiary of the trust, me and my siblings are 2nd, 3rd, and 4th beneficiary’s)Yes, it already had a home on it.

All these investments after all the years are worthed as kid would finish their university with zero debts zero student loan , and he got 6 digit income even before he graduated.invest in 401k/529/Ira/real estate is all worthed…Personally I don't like 529, I prefer Coverdell/Education IRA , where you can also invest in Real Estate and you can use the funds for school (ie K-12), and if your Kid doesn't want to learn, you can transfer it to a sibling.

The Tucson house was a complete surprise when a friend told us that their father had passed, and her and her siblings just wanted to sell it and split the money.

I'm from Massachusetts; I had breakfast with an old friend and she mentioned that her family has a property in Shenandoah VA that 3 of her siblings don't know what to do with it.