However, I never have people come to the house if I can avoid it, simply because it's none of their business where I live and there are some crazy people out there.  

As someone else pointed out, a first-come, first-served policy will also help avoid claims of discrimination.

Sounds like a desk appraisal is just the thing I am looking for as I was hoping to avoid a full blown $300 or $400 appraisal.

Many of these tasks you mention are part of the cost of doing business, such as periodic painting and replacing flooring (see some of the discussions on products like Allure if you want to avoid carpet issues).I think you have gotten more than your nickel's worth on this paint job and flooring, and even the most frugal landlord would want to redo these at this time (turn over is the ideal time).

I want to avoid having to go to different places in different areas to get pre-approved, each time getting a small mark on my credit history.

BP here's some terms to consider for your business model: competition avoiding, selects for hardy customers who stick it out, tolerant for varying quality in the finished house.  

It is interesting to note that your wife would be a disqualified person with respect to your mother's 401k even though your mother would not be disqualified relative to your wife's plan.Again, these prohibited transaction rules and the avoidance of disqualified persons does not apply to funds that you have borrowed from your 401k via the participant loan feature.

I would also add that I am a firm proponent of avoiding lifestyle improvements that come at the cost of your financial health.

An s-corp is not a good place to hold rentals.Another thing to look out for is if one of the partners is a licensed and bonded contractor and you are hoping to avoid sales tax and B&O tax.

We have investor clients who will make offers on the properties, which can help the homeowners avoid foreclosure.