You don't NEED a realtor to complete a residential real estate transaction although they can certainly be helpful - it just depends on your comfort level with owning all the steps yourself.   

Personally i dont want to do engineering forever, every upper level engineer i know works crazy hours and the stress level seems high.Good luck in engineering and real estate.

It depends heavily on your personal comfort level with making managed risks like this.

It depends on your comfort level.

You can get a nice house with low vacancy for around $60,000 sometimes even lower. and those can rent out for $600 to $700 dollars.

Most of your residential units are lower income but there are some pockets of better income.

I have properties that range from about 40-62.5%, it's all property dependent with rental price being the biggest factor... higher rents, lower expense %... that $4k HVAC costs the same wether the place rents fro $1k a month or $500 a month, but you're looking at 4 months vs 8 to pay for it. 

None-the-less, I think it would depend on what level of involvement you want to have.

@Mike Robinson - Some thoughts on those lower priced MFH's we were discussing.

The deductions simply lower your taxable income.