The tithe was given on "the increase" not the total, and I think that is a reasonable look at how to determine what to give on....but again it is a matter of the heart, it is not a law to be followed. 

As you gain experience, you'll determine where your talent lies and how to proceed.

I would contact the housing authority who manages the S8 program in your area to get an accurate ideal of how they determine what they'll pay on the tenant's behalf.

If you have them for more than 2 years they look at your tax returns to determine whether you are making money or not.

However, many real estate investors use the inspection to determine if the property is a good investment.Here’s more information about these two steps:Home appraisal: Mortgage lenders require a home appraisal to ensure the sale price represents its current market value.

First I would try to determine what happened.

I've established a very stable  I've determined that local properties should be my first choice and by local I mean within 1.5 hours of my primary residence.

That will determine if you claim this on a personal return or other type.

In addition, the appeal process is filled with subjective determination. 

You should determine, are the returns strong enough to justify paying some UBIT, in comparison to investing in other investment products, such as what your IRA is investing in now.