However, even in these cases, you typically leave a small amount of money in the deal and only break even before accounting for vacancy, repairs, and other expenses.

FHA loans are a great way to get started with a small down payment, but make sure you have some reserves for things like repairs and vacancies.

You can expect turnover costs, losses due to vacancies, and other expenses.

It can make leasing a bit harder since you will have more vacancy when those come do but it will all be in peak season.With respect to the hiring decision, you would need to hire someone to replace you (perform the same functions you currently perform) so that you continue to work up the ladder (spending more time on higher value tasks).  

* Does it significantly affect rental demand, vacancy rates, or rents?

However what happens when the tenant vacates and now the unit has to be turned over/takes a few months to find a new tenant and during that same period of time the sewer line goes and you get hit with that $15,000 cap ex expense in addition to the vacancy and turn over costs.

We have had it as a rental for 5 years now and have had only 15 days of vacancy. 

. $150 cash flow on any rental especially a triplex is dangerzone imo. 1 month of vacancy of 1 unit could destroy a years worth of financial gains.  

By investing in metropolitan areas your yield would be lower (6% to 7%) but you would have a lower vacancy rate.

Purchase price: $85,000 Cash invested: $33,000 Cash flow is after all expenses including vacancy, maintenance, and capx deductions.