House hacking is an awesome option and could have worked very well for me, but ultimately didn't fit what I wanted for my personal life and goals.Therefore, I think looking at additional properties instead of trying to house hack is definitely a possibility if that is what you would prefer.

I do upgrades periodically but prefer to do them when I am not raising their rent.

The easy and preferred answer is to tell the truth.The more difficult answer comes from figuring out if you lose more by telling the truth or by lying.

We just need to find our niche.

It appears to me that the most successful wholesalers began in another part of real estate and found their niche in wholesaling. 

Could do cash-out refi but would much prefer to do a HELOC to avoid paying fees on money not used.  

You need to find someone who is willing to sell to you with low or no money down and take payments--preferably another landlord who is ready to be done with it. 

To each his own how you prefer to analyze rental properties though.

Since they are not the best tenants, and you'll probably prefer replacing them, so what if they get annoyed at your "lack of customer service?"

So, I don‘t know the real estate niche you have been focused on, I‘m 100% focused on a different niche.