In NYC transactions, property taxes are pro-rated and sellers + buyers pay for the portion they're responsible for (depending on the calendar schedule of the county + closing date).

They want to send me to the commercial loan department where the rates are awful, closing costs are high, and the requirements much more robust.What if I just get a second-home construction to permanent loan, wait 12-16 months for it to be built, spend another 90-120 days furnishing it, and then refinance into a traditional 30 year fixed as an investment property?

We have also had, historically, a 5%-ish difference in rent rates when renting out in December and January as opposed to other months.

So I was thinking of a $100 increase to cover the $50 mtg rate increase plus $50 to get close to market price.

He is looking for $290,000 but realistic offer price with the current interest rate and other expenses is closer to $260,000. 

Just looking simply at rates may trap you in a way..

I am thinking if we bought it for my mom it would be with the understanding that we wont make anything on it until we resell it in a few years, looking at rent in the area it wouldnt cash flow if we were to rent anything out with the current rates.

LOL this is the first area in columbus i've analyzed where property values went down at 2.31% decrease year over year.

Also, remember that interest rates are also negotiable, and the seller gets all the money from the interest. 

(Quoted about 8.5% rate on a DSCR loan, and budgeting 10% of rents for capex, 9% for PM, and 5% each for vacancy and maintenance) After-rehab rents would be about 1350-1500 based on comps.