Everyone wants free tax advice. 

I have used him for over 20 years and has been great but I want to make sure he is not missing any tax benefits for STR.

Hi, I am seeking advice on what kind of entity I should form for tax lien investing. 

If you are setting aside funds for capex, taxes, insurance, or other expenses that don't occur monthly, transfer those funds to Savings each month and hold them there until it's time to spend them.

We as a firm have investors working with us who have rental properties all over the US big and small.Finding a real estate-focused tax professional and one who can help with advisory and grow with you would be my suggestion to focus your efforts on finding.

Property taxes here around around $10k/yr so around $800/month.

Behind on property tax?

So far, I am in the midst of purchasing a couple of mortgages and I have purchased tax liens and deeds. 

I am also including the taxes and insurance while running the numbers.

.- Document everything (receipts for taxes, all the work that you did yourself via photos and video, and your expenses in an excel sheet to make sure you're on track.