There are rentals, fix and flippers, lenders, tax liens, note investors, STR, commercial etc.

I make around $110k+ per year, live off around $75K, have a mortgage ($1900/mo for rent, escrow, tax), around $40K in equity, and no other debt. 

.: What is the average conversion rate for cold calling using software like PropStream, specifically targeting probate, foreclosure, or tax delinquency leads?

When you sell, interview as many as you need until you feel very comfortable with the one you decide to work with.real estate is a big investment, and for me it's long term, I don't want to have buyer remorse because someone isn't as knowledge as I like.when I was younger,  I was more willing or less experienced,  today I want the same level of knowledge as I offer when I help someone with their tax planning or when I prepar their taxes.....Show me your high level of knowledge,  you are hired.

That's 50k a year gone and you are losing tax write-offs and equity potential.

You are hopefully getting good cash flow, appreciation, mortgage paydown and tax benefits.   

I want to take advantage of growth if possible, but also want to minimize taxes and fees (penalties).

Quote from @Erick Pena: A "good" rental property is one that covers all expenses (mortgage, taxes, insurance, maintenance, property management fees, and any other costs) and still leave a surplus (commonly referred to as cash flow).Calculate cash flow as: Cash Flow = Rental Income − Operating Expenses − DebtThere's much more to it, but that's the basic idea.

Credit is a factor as bad credit may limit options, or may have the lender require you to put 10 or 20 years of taxes and insurance into escrow. 

If you need financial help, ask under the "Finance, Tax, and Legal" forum.