Here are the numbers:142k principal balance156k accelerated balance due to past due paymentsSeller only wants 5k out of the deal, I offered 165k (redfin estimate is about 217k, for whatever that is worth)Right now my only question is, how is the best way to go about this?

If so try to get an idea of what renovations would cost.Once you get an ARV and Rehab estimate you can determine a reasonable offer.As far as the Financing goes I am a firm believer in using as little of my own cash as possible to invest.  

How to estimate homeowners insurance cost (usually just go by redfin's estimate, but I would like to use something more accurate)?

The question is: Should I consider the realtors estimate, which is below Zillows! 

If you contact an abstract company they should be able to give you an estimated closing clost just check with your bank to add in their requirements Regarding transfer tax and property tax you can structure this any way that you and the seller agree.

I have only gone as far as receiving an estimate from Fast Track Remodeling to renovate a rental property in Houston.

.$145,000PURCHASE PRICEPurchase Closing Costs$2,000.00Estimated Repairs$20,000.00Total Project Cost$167,000.00After Repair Value$170,000.00Down Payment$7,250.00Loan Amount$141,882.50Loan Points$4,132.50Amortized Over30 yearsLoan Interest Rate5.400%Monthly P&I$796.71Total Cash Needed$29,250.00Monthly income:Rent:$3,500.00Other:$0.00Total operating expenses:Mortgage expenses:Vacancy:$350.00Repairs:$350.00CapEx:$350.00PMI:$40.00Garbage:$20.00Insurance:$56.00Management:$350.00P&I:$796.71Property Taxes:Total Monthly Income:$3,500.00x50% for Expenses:$1,750.00Monthly Payment/Interest Payment:$796.71Total Monthly Cashflow using 50% Rule:$953.29I made conservative estimates on everything.

like it says just estimating but I found mid term play not a flip from a foreclosure of an entire property management business, small business.

Get a conservative $/psf in which you can use to estimate your rents.

Bought in 2015 for 210k, Zillow estimate at $370k (so let's say $340k on the safe side)3.