It is my understanding that the new owner will have the house at the cost basis of my purchase price, for calculating capital gains taxes or depreciation.For gift tax purposes for you - FMV.For capital gain tax purposes for the recipient - your original basis/purchase price 

Disallowed losses under wash sale rules increase the cost basis of replacement securities, potentially reducing future taxable gains.This post does not create a CPA-Client relationship.

HI @Jimmy RojasYou have to show 2 years of taxable income to the IRS.

Leftover funds not reinvested are taxable as "boot."

My understanding is profit from lending is considered "taxable income" and is therefore added to your income and subject to your normal tax rate after all deductions, etc.

The value of the property and how it’s distributed relative to ownership stakes will determine whether it counts as a taxable event, I believe(I’m not a CPA or attorney). 

Quote from @Mani Sundaresan: If I’m financing a rehab project with a hard money loan, do I still need to issue 1099-NEC forms to my contractors—given that the funds come from a loan, which isn’t taxable income?

Yes, Spain has a wealth tax but it's above €2 million taxable income and the rate is low so it's not going to kill you.3.

I have dabbled in real estate, but never heard of brrrr before now, and transparently never did much research outside of knowing that property ownership was a way to reduce my taxable income. 

Tax benefits should be considered but not be the sole factor.The 'main benefit' from a tax perspective should be to generate a high return from your real estate investments and not to pay taxes on the return that you get.If you are able to reduce your taxable income, that should be icing on the cake.