Paying taxes on money you should receive does not apply in this situation and is much more complicated than a simple RE transaction. 

Your top 5 quick metrics you look at before moving on to a different property or performing some more complicated calculations...Not sure if this will help but I am located in Northern California, 23 years old, $90k salary, looking into SFH or small multi-family (duplex/triplex) to start out.

It's complicated, but not impossible.

Landlording gets so complicated when you make exceptions or think “well what if this *insert random thing here”.

Downside is assignments are inherently complicated and require you to have a well networked agent to find.

I bought another apartment (in another state, because why to make things easy if we can do them complicated) and this one brought me 10k in one year just because of the price of the apartments at market went up, so lost here, won there.

If seller is reaching out to someone else to get property sold then they might have an issue with paying the agent’s commission if you bring the buyer into the picture which could make things complicated. 2.

Seller-financing can create complications, depending on the arrangement between the two of you.

That is a far more complicated conversation regarding Qualified Business Income and Sec. 199A, but may be worth speaking to a tax professional about.

It really doesn't matter for small taxpayers becuase there is no interest capitalization and other complications, but the logic would be same, wouldn't it?