If the utilities are the tenant responsibility, and they are off, you MAY be able to declare the unit "abandoned" and take possession, but this is may be IFFY!

Do I file a pay or quit (not trying to get him to pay anything, just vacate), or just go for an Immediate Possession?

If nobody bids at your foreclosure sale, then you will get possession of the house, but the first will still exist. 

Delay closing or hold back money until you have possession.

He can tell the court that he is not chasing them down for past due rent for 'brownie points'; The most important thing is to regain possession of the property.

To find, identify and execute strategy to successfully complete home runs, you'll need knowledge, experience, smarts and capital - a combinations most small part time investors don't possess.  

If I wholesale a property (true wholesale where I never gain possession, but do get the assignment fee), does the income count as a capital gain that I could then reinvest in a Qualified Opportunity Zone to shelter it?

The issue in this house was that the sump pump failed after the bank took possession.

For about 20 bucks a month, give or take, their possessions will be insured against damage.  

Here is what my team sends out...I am in possession of an assignable Purchase Agreement that will allow me to purchase a home on NW Breezy Brook Ct in Port St Lucie, FL.