Don't buy it" But I've got several in your market so I'll do my best to answer your questions! 

A final choice would be to rent the primary in a few months, reside in a rental for several years, sell the primary, and purchase another SFH for rental and a SFH residence as a new primary.Is this a viable place to begin investing?

Deciding whether to hire a property manager depends on several factors, including:Your Availability: Do you have the time to manage tenants, maintenance, and legal issues on top of your existing responsibilities?

Values drop, sometimes drastically, rents go down as quality of tenant declines; cost of operstimg properties increase, and governmental interference, especially in the form of rent control, can slash values and profitability severely. 

I have bought several properties in Texas while living in England, where we never stepped foot into the property, but they were newer homes and no repairs were necessary.  

I've been flipping houses and investing in multi-family properties for several years now, but I've hit a bit of a snag recently.

I'm not saying you weren't, but I know architects and engineers, if they get a feeling that a client doesn't really know what they want and will need an excessive amount of hand holding and doing several redesigns through the process, they will pad their numbers.

The roof looks in relatively good shape (I don't know the age) although I did notice a very small leak in one part of it and the facia is rotted in several places. 

You will burn through several of each before you settle on a more permanent person, and even then they can disappoint at any time.2.

I have done several as you explained.