There’s almost always a rate at which it just doesn’t make sense.

The "variables" you speak to could mean this is worth every cent of a 5.4% cap rate to "I wouldn't touch this for a 12 cap".  

Hence the lot on which the house resided was taxed at a 45% discount based on actual value, while the tennis lot was taxed at about 4 times what it should have been by value. 

There are many tax accountants on Bigger Pockets that can help you with your situation. 

My suggestion is to find some real estate industry surveys (via CBRE or others) and look for the MF cap rates in various cities/states/regions.

If your friends have a rental they should hire a tax professional. 

Looking for various tax strategies to reduce the reality that a large RV or boat is a grossly depreciating assetI would not have a loan, so claiming it as a primary or secondary residence and claiming the mortgage deduction is not applicable.I sold my primary residence and I have several rental properties which I use as I'm fixing them up.What I'm pondering is living aboard and working aboard developing a new product, while traveling.  

If you can’t do a 1031 to a non-income tax state, figure out a year when you will have lower income and tax rates ar as low as possible.

Yea they would keep that in place and you'd get a second position mortgage for the rest at, well, higher than todays rates.

You can try and fight it but does not mean you will be successfulI would also be curious to see what your property insurance looks likeFor me this is just another example that home prices are gonna eventually have to soften as between taxes, insurance and Interest rates home affordability is very challenging