If you can't afford the down payment, what will happen when you a big cap ex item arises? 

Re just a 1031 exchange and through a brief phone conversation with an RE attorney, I was advised that I could take a percentage of the profit for personal use and be taxed on that portion, while leaving the rest in the 1031 for purchase of similar income property. 

Especially if the tenants have small children, you have to clearly communicate what items are forbidden to go down the toilets (baby wipes, bleach cleaners, etc) and let the tenants know if they plug the system they are responsible for having it cleaned out/pumped. 

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Again, don't start your conversations with the seller by asking them to carry a note.  

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I am trying to understand the safe harbors as it relates to expensing rather than depreciating items. 

Some of these “big” items are either issues that have been dealt with or will likely need to be dealt with.

But items like knob and tube or old plumbing might be less marketable, it won't affect the value of the house in comparison to the cost to remediate.