Best of luck to you -

So far, the best deal I have been able to find is 5% down with no PMI (80% from Fannie and another 15% from a second lender).

Well, this my opinion, if you like unpredictability, constant change and people/contractors with no regards to you or your property then "YES" flips and STRs are the way to go...LOL....I love it!!! 

Not the best scenario but installing new systems can mount cost quickly. 

Can you share the websites you use and other ways of finding properties to buy?

DENVER — Rent costs in the Denver-metro area recorded the largest monthly decline in the nation in January, according to Zillow’s monthly rental report.Denver was one of 11 major metro areas where monthly rental rates fell, leading the way at a 0.4% decline in January rent costs, the report shows.

What are some ways I can verify that tenants are protected throughout the entire lease? 

If you have an actual lending strategy then different loans will serve your overall portfolio goals in different ways.

For Non-Admitted carriers, the important item to then pay attention to is the AM Best rating (or equivalent rating agency).

If you want an easy way to visualize your rental finances, there are some solid bookkeeping apps and spreadsheets that can automate a lot of it.