He confirmed my assumption that the estimates on Zillow, etc. are pretty much junk, that they will regularly be at a minimum 5% off, sometimes much more, and that what he has seen in the past is that new investors have based their numbers (purchase price, rehab budget, etc.) on these inaccurate numbers and what started off looking like a great deal, turned out to be a bad deal for them after the actual comps,  inspection, and assessments. 

Here's my assessment based on what you described. 

What I would do when beginning my journey is assess my current situation and goals.Are you open to owner-occupying your first investment?

Meet them in person and ask as many questions as possible to assess if you will have issues with them5.

I'm not sure that someone's past performance in the market will be helpful if you are trying to assess your potential future performance.

Be prepared for this aspect when assessing and analyzing deals.

Restoration company, with a $500 deductible for home insurance, is drying and working on fixing tile that is water damaged, grout that has eroded, drywall that needs replaced, etc etc.We have about a dozen examples of issues similar to this.

Got hit with a 24k assessment 1 year after purchase, but we are still cash flowing and got the condo at a great price, as well as at 3.25% interest.

Such environmental due diligence is typically performed by retaining environmental professionals to conduct a “Phase 1 environmental site assessment,” and if necessary, a “Phase 2” and “Phase 3” site assessment.

I currently manage dozens of homes with septics and have bought/sold dozens more.