If you spend more than you make, it's a very dangerous financial position.

Second position loans are particularly dangerous and, in my view, only for those who do this professionally and who can withstand getting wiped out on occasion.

They basically hold the building liable rather than the owner and that liability transfers from owner to owner until someone deleads it and breaks the chain. 460.100: Duty of Owner(s) of Residential Premises (B) Whenever any residential premises containing dangerous levels of lead in paint, plaster or other accessible structural material undergoes a change of ownership and as a result a child younger than six years old will become or will continue to be a resident therein, the new owner shall have 90 days after becoming the owner to obtain a Letter of Full Compliance or a Letter of Interim Control, except that if a child younger than six years old who is lead poisoned resides therein, the owner shall not be eligible for interim control, unless the Director grants a waiver pursuant to 105 CMR 460.100(A)(3).

Or am I better off finding an area where they have fewer duplexes/multi families?

Repetition is useless (dangerous in fact) if you're failing to account for local customs, extra costs, restrictions or you're using now-baseless assumptions.  

That is where you can run into problems and dangers if you are not careful.

I’ve been a realtor for 11 years and the past 4 years I’ve been with the same brokerage.I work on a nationwide investor-friendly team, (teaching agents to become investor-friendly and to become investors themselves).Working with investors allows you to work with fewer clients and do more deals.

The Zestimate for my personal residence is 30k lower than one of my direct neighbors despite the neighbor's home having fewer bedrooms and bathrooms and being 800 sf smaller.

For example, I could put the entire $215k towards larger down payment on fewer properties, and thus keep reserve needs lower, but I’m uncertain if I will get the $1500/month cash flow desired.

Tenants will have 3 options to by-pass security deposits:  1) Apartment security deposit insurance, which may range from $3 to $20 a month paid during the duration of the rental, depending on the monthly rent. 2) Installment plans, which would be paid over no fewer than six months. 3) Payment of a smaller security deposit, which must be less than 50% of the first month’s rent.