I've encountered plenty of hurdles and stressors, especially given the unforeseen issues with the market, financing or tenants in general.

The rule he'll encounter is the 100 mile FHA rule.It can be planned around but he would have to move out of the current residence first for 6+ months then apply using FHA from the hypothetical rental to purchase using FHA (mortgage planning counter to the rule).He could also use conventional 5% down (Fannie or Freddie Mac) to avert the situation above with FHA since conventional does not have guidelines that put conditions upon obtaining subsequent properties (such as that 100 mile FHA rule).

If you want,  I've got some resources i can share - investor package, contractor referrals, and neighborhood map.

Search the BP for ADU appraisals to encounter numerous examples.

I have a scope of work document, investor package, and strategy info if you want. 

Because it takes repetition for people to remember things and you have to be top-of-mind when they encounter a potential client for you!

Quote from @Lakita Woodson: As landlords, you may eventually encounter a tenant who seems to damage something every month right after paying rent.

We work with builders form a large number of markets throughout the country to package New Construction investment properties. 

I can share dm you my investor package, contractor sheet, and neighborhood map.

Quote from @Kay Nemen: Quote from @Russell Brazil: Like any service based business, you're going to encounter a variety of types of fee structures.