Where as your mom is likely paying the taxes, the taxes are going to be eventually a deduction from the other siblings share.Go on line find out who's name the property is in, so you know who's in charge,, Somebody also has to be paying property insurance, utilities, ??

That's a bummer, but keep at it, and it will eventually stick... with the right property.

His goal is that we would eventually own it outright and could to either sell it or rent it out as a vacation rental without having to wait for transfer on death were they to live another 30-40 years.

I want to eventually own multiple investment properties.  

Basically a point of contact when I eventually have to move. 

You'll get the same tax benefit eventually, it just comes over a certain time based on category.  

Keep plugging away and you will eventually find a property that has no, or manageable, foundation issues.

You purchase the home/property paying the principal/down payment and then you either rent it and pay down the mortgage with the tenant's money/money you pay during vacancies and eventually sell it after/if it appreciates?

Our plan is to be able to raise our family in this home, and eventually, take some money out to buy a few more 3-4 unit buildings.

Eventually you will want to make the leap over analysis paralysis, but that time may not yet have arrived.