These activities by a disinterested third party would be considered real estate brokering in my state and require being run through a licensed real estate brokerage.

I plan on getting it resolved as soon as I can, but I'm looking for insight into whether the best course of action would be to call in an exterminator now, vs taking care of it myself, which is how I've always gotten it done in the past.My tenants leaves food for her cat every morning, and has found ants crawling over the cat food for the third time in two weeks.

If you were to go to a third party lender on this size deal, the loan would have personal guarantees so that inherent in the seller financing is the concept that to sweeten the deal, the seller is providing you an economic advantage hence the higher price.

all the meters for the second unit include the third and second floor.

We've gone over this before: The 'Financial Analysis' tab shows the year-end financial performance of each property. 

Under TRID, changes will be made to the following processes: The Loan Estimate must be placed in the mail or delivered no later than the third business day after receiving the application and no later than the seventh business day before consummation.

People that don't perform reasonably I don't call back so I have subs and GCs I use regularly and they take care of me. 

I believe I would like to be in the buy and hold area of investing, however I would like to perform 1 fix and flip over the next 6 months. 

Many real estate strategies I've heard of go along the lines of using a third parties capital to fund your investment.

Assuming this is performing loan, your annualized yield would be ~65% at that purchase price.