It has made a huge difference for me understanding my data and I have nothing negative to say about it at all. 

My understanding is that when renting out rooms in a primary residence, the income is classified as boarder income and isn't counted towards DTI, as outlined in Fannie Mae's guidelines(https://selling-guide.fanniemae.com/Underwriting-Borrowers/I...).

I think this is a solid deal if you are happy with the more significant downpayment. best multi family deals I have seen on the MLS or off market have all been seller financing in the SLC valley over the last year.

If you do this you can potentially include a higher security deposit but you want t make sure to follow state laws about that.I understand that people may be improving their credit due to life circumstances.

You've got a solid plan.

I understand you tried that and it was rejected but I think you just need to keep putting offers out there. 

MY biggest concern is when it comes to understanding the market changes and how to analyze what city is best.

The lake is right there for summer and of course skiing.I don't know about the rules around STRs in the area but it seems like a solid choice.

Verifying last 2 years of rental history and income extremely important to find the “best of the worst”.Make sure you understand the Class of properties you are looking at and the corresponding results to expect.What else can we assist you with?

I understand the importance of time so i do not want to waste anyones time.