Lets just say worst case scenario you spend your 20's working hard, living lean, and investing every extra dollar.

I work a 9-5, am married, and have 2 kids under 3 years old so I don't have a ton of extra time to actively find, fix, and flip properties.

., curfew, no nights out, extra chores, eviction, etc.AH, eviction.  

Use the "extra" income to build a reserve for maintenance, vacancies, and other expenses that don't happen regularly.

If everything else checks out we ask for an extra deposit or advanced rent.

At a minimum you can put your extra funds into a high yield savings account, or even better 4-week treasury bills that give you state tax exemption and keeps you liquid for your next acquisition.

They see the lower rent and don't factor in the extra expense. 

Well, do they have a job to pay that extra $200 plus utilities per month?  

Sure, if OP wants to spend an extra $500-$1,000 on an appraisal that can't actually be used by her bank just to have as a reference point, she can certainly do so.

We do get a better fee/split structure, and that's a fair trade for the extra work of managing a large investor base and it's associated extra accounting and tax reporting overhead.I also find the advice in the OP to be contradictory.