When an individual landlord prices their rental, they do based on what the other ones in the neighborhood have rented for. 

Does anyone have any tips/ advice to help make sure my property will appraise for what I planned on based on my rehab?

Is  this based on one of BP's deal analyzers?

Spending on expensive upgrades is not the answer to improve your tenant base in this type of area.Keep the homes habitable, clean, and safe. 

Based on comparable listings recently sold I think closer to $650k there would be more interest.  

This is how much you need to increase your room rate to become profitable based on last year's information.

DSCR loans are based off of down payment, credit score and either actual or market rents so it helps to supercharge an investor's real estate goals and net worth.

Whether To file a 1065 partnership return or being treat it as a disregarded entity, Is the determination based on the location of the property or the owners' residence state?

Again, this is only based on info you provided so there could be a lot more to the story for the good or bad but I can only comment on what was provided. not sure many are thinking rates are going to drop much in the next year.. seems like one would want to know how much they need to drop to see if the plan will work before putting good money after bad.

I see the base interest rate for federal lending is 4.25%–4.50%.