Good credit score (800+) but low income ($70k)Candidate 2: Family of 5 (3 kids) with a business + a smaller dog (40 lbs bulldog) and ok credit (680+) but higher income ($130k) than other candidate. 

In my current analysis, I'm (trying to) take that into account during our "move out event", including converting to a conventional loan, renting out both units, etc.

These are a few things I would do to insure accountability. 

With $600k in pretax income I would imagine you could use some write offs.

But we can afford that (our current bay area home is paid off) and we have a regular income & no other debts.  

That being said, income limits will also apply when exploring the USDA loans. 

We are searching for new tenants and are considering a tenant who has plenty of income and >800 credit.

However, there is a tax deferral strategy that could accelerate your depreciation, keeping more money in your pocket today, known as cost segregation.A Cost Segregation study is an IRS approved federal income tax tool that increases near term cash flow by utilizing shorter recovery periods for depreciation to accelerate return on investment.

How good must they be to set up a bunch of fake accounts to comment. 

The city's diverse economy, favorable tax environment, and high quality of life attract a steady stream of new residents, ensuring robust rental income and long-term growth potential.