They're not going to add much cost to the permit and you want to make sure everything you do is up to code.

zip code 15132. near myer park

Modern codes might require 5 in a room like that.

I love Cross Country specifically because they can service their own loans meaning that they handle all the construction draws and payment processing.Plus, I like Homestyle over 203k because they don't have as strict of guidelines on what has to be renovated.

When speaking of a strictly commercial loan that is a different animal as is not 2 units purchase first time buyer which @Thomas Lebens states he is. 

Quote from @Hector Espinosa: Hi,I'm negotiating a seller financing deal which may be my first one and would like to ask for some advise about and what are advantages and disadvantages about seller financing deals.These are the seller financing terms:House Price: $330,000.00 USD​ (Sellers still owe ~$301,000 USD)Down Payment: 5% = $16,500 USD​Loan Amount: $313, 500​ (Monthly payments will be amortized as a 30 years loan​)Interest Rate: 4.531%Balloon Loan Term: 5 YearsMonthly Payment (P&I): $1,594.24​Closing Costs:  ~$3300 ​Zip Code: 74105Observations:       * HVAC requires an update but pending to inspection (replacing with a new one will cost ~$10,000 - $15,000 USD )     * Expected Rent Income: $2,000- $2,300 but this is has been really complicated to get a good estimate because is all over the place in the different sites I have checked

I am thinking I'll have to set aside expenses to redo the wiring, plumbing, etc and bring them upto code. 

I do know, however, that they are pretty strict about the STR activity in the area. 

Is it better to purchase property as Vacation Rental STR, and then decide to switch to Long Term Rental if the regulations become more strict?

Because these communities would be in smaller towns and rural communities, the licensing jurisdiction is the county, meaning that code requirements are more often vested in the fire marshal and are less onerous than city requirements for the buildings and the site improvements.