Next summer my wife and I will PCS (Permanent Change of Station) to Norfolk, Virginia.

Property does have to be in rural areas, have to be permanent resident and cannot be a income producing property.

Is it maybe even possible to choose a different siding over the brick, to encase it more permanently?

@Cordell MartinIf the tenants are concerned about paying for a system that is permanently attached to the rental unit, they can check into SimpliSafe. 

Then of course you have permanent competition in renting or selling of the condo, and since the exterior is the same, you'd better have the best interior.

RESIDENCE Definition & Legal MeaningDefinition & Citations:Living or dwelling in a certain place permanently or for a considerable length of time.

Letting your in-laws take two years to get fully acquainted with their chosen retirement location while keeping their former primary residence let's them change their mind if the retirement location is not meeting their expectations.On the other hand, if after two years, the in-laws have settled into their retirement lifestyle and want to stay permanently, then they can sell the former primary residence and use the sale proceeds to buy their new retirement home while still keeping their capital gains exclusion on the sale of a primary residence intact..  

But on closer reading it appears to give the Property Manager a permanent veto over anything a customer might say about them in a public forum.

You could get a conventional loan for house hacking, and potentially put 3-5% down, and not have the restrictions that FHA loans come with (e.g. permanent mortgage insurance, only one at a time, etc.). 

Many Sellers will prefer your offer of Cash over another that is conditional on Financing.After you purchase the new Investment property you will want to Refinance it so you can pay down your LOC as it will probably be a little more expensive than the permanent mortgage you can get on the Duplex.