Twice as many doors will result in twice as much vacancy over time.

With rents usually due on the first, and utility bills rarely matching the dates of the rent, it is difficult to allocate rents and the beginning and end of rent periods.

This way, if your roommate is not a good match for you, but they're doing nothing that violates your lease, you can just give them the 30 (or 60 day if that's what your location requires) notice to vacate immediately.

The seller has asked me if I can match the APR of 6% which he is currently paying.

Kind of like if you were a quarterback and you had to audible in the middle of a snap count, in order to read the defense and call the play to match what they were giving you. 

Similarly, I do not expect in most areas of San Diego the STR regulations will have much impact on the rents.However, certain beach communities, such as Mission Beach where our STR is located, have enough STRs that there may be a resulting price decline but I would not view the price decline as a price reduction because the profit of the RE is substantially different when it cannot be used as an STR.I will use our STR as an example. 

My BIL is on oxygen and the last two power outages in Raleigh (storm related) have resulted in his being hospitalized.  

It seems like a total waste to not use the money on a property (it’s a 4 to 1 match grant - so I saved $2k and will be given $8k), so I’m looking into using it for an investment property now.

In 1 to 4 units I find it often results in a short term hit to the cash flow. 

However, one of the tenants is exploring job opportunities that could result in them relocating in January or February.