I am going to target new builds in the future because the seller has less of an emotional tie to the property.

All of my investing has been fraught with emotional drama.

My advice would be to not buy with any emotion. 

In most cases you cannot charge two different tenants for the same time period (double dip).Pet fees/pet rent: Local laws vary, but there are often addiitonal deposits, fees, or rent for allowing pets that don't qualify as service animals or emotional support animals.

How can I keep my emotions in check and treat this like a business?

Real estate can be emotional and you want to make sure you keep emotions out as much as possible so you can think clearly about your options.

The emotional ups and downs involved in evictions and collections are truly unique.

I would say raising money is harder than finding deals, because investors have emotions you have to navigate, where as the deal numbers are straight forward. 

Ad hominems make for a weak response.So do emotional responses.

Unfortunately I’m emotionally tied to it since it taught me the most I have learned good and bad.