The reason it's so powerful is that you will be buying a property to live in (primary residence) that will also be an investment.

What would be an practical cost/ cash flow annually ratio to decide if an area is worth investing.

I'm happy to grab a coffee with you if the later. 

I live on the south shore but I am down the cape a lot and would love to grab and cup of coffee and conversation sometime. 

Also, there will probably need to be an independent wire run for the microwave, dishwasher and garbage disposal.

I forgot to add that this will be an FHA loan 3.5%.So I will finance the entire house and house hack the top floor.

This could be an easier and cheaper solution than hiring someone full time.If you are just looking for someone to answer the phone and contact your list of contractors, I'd suggest looking into the "virtual assistants" that are featured heavily on Bigger Pockets podcasts as this seems to be a very cost effective way to manage the day to day without putting in much money. 

I have helped people OOS build their teams here in Indy, so with you being local now it might be an easier process to get you started.

They typically prefer accredited investors, but you may be able to join some syndications without be an accredited investor. 

A few ways that may help increase your reserves would be an FHA 203k loan or equivalent lending program which would allow renovation costs to be added to the loan.