If they are professional, they can explain this quickly and easily.

I can show you more easily than tell you.

My dad's also been in construction for 30+ years and can easily work on fixer-uppers, but I'm generally risk-averse (and it's my first property) and don't want to encounter a host of unforeseen issues.

Once you’ve identified a broad area, you can easily whittle it down.  

If you have a job you should easily be able to refinance, or get a HELOC on your primary residence and pay it off.Credit and DTI have nothing do to with sub2's.

I found Cassie easily. 

A two family that needs less than 30k rehab in Worcester is going to be 350k+ easily in a good neighborhood.

Also, you can The the flipping easily with conventional renovation loans with FannieMae Mae HomeStyle which investment properties, 1 unit, 15% downpayment 

Meaning do they have high enough reserves, insurance, low enough percentage of investors units, enough individual owners, etc to make it easily financeable.

You can easily hit the 1% rule here and expect quality tenants.