If the calculation is equal to 1 then you are not making money, 1 represents that you have enough cash flow to cover your dept. less than one means you were not making money and greater than one means you have a cushion and making money. banks look for above 1 because they want to make sure you will be making enough money to pay them back and that you will have the money should costs rise and change your NOI, I know my bank looks for 1.25 DSCR . usually they just do not look at the properties, they will look at your personal situation ( credit card dept, alimony payments, medical payments) especially if they want you to personally back up the loan. there are a lot of explanations and probably better than i explained, all you have to do is look up DSCR, hope that helps.

After you're done with that you can always buy a single family to start a family in if you need to.I think it's the best strategy to get started and make a big change in your financial position!

Generally, you get hold of city planning department as the first step:Springville City planning Refer to the part on change in zoning and call the number, if the house is in Springville UT.Processes differ everywhere.

Can I have the Seller change the sales price to 600k? 

Changing to your lease probably won't change anything.Personally, I would notify them - in writing - that I intend to "renovate" the unit when their lease expires and that I will not be renewing.

they did say however that it could be made livable again and status changed if we repaired it and had the required inspections done.

I would double check with your CPA , because the interest carry law changed and it effects class S or C or LLCs' ...

If you set up the loan as interest only, the principal won't change. 

The technology is unlikely to change that substantially in 15 years, and panels typically have a 25 year warranty. 

most local banks will try to have you on 20 years which changes the numbers and cash-flow.