Every market can be invested in successfully.

It justifies the property selling for greater than just market appreciationI do owner builder rehabs but sometimes use contractors for large work scope or scope beyond expertise.  

I would rather invest in safe markets that produce a good return, then I can use that income to pay for a vacation anywhere in the world.I'm very pessimistic about the STR market in Hawaii.

Flipping houses is a great way to create huge profits, raise private money and create marketing content around your remodels (the reason HGTV is HGTV).

There's a reason that people try to buy properties off-market and that is because you can find sellers who care more about terms than maximizing returns.So start with a conversation: you already presumably have some rapport since it's your landlord and you've spoken before.

Are you trying to buy in your market?

In my market, I only have one vendor qualified for appliance warranty work, and the warranty companies paid him half his standard fee for each service call. 

I know a little about the phoenix market and agree it is growing. 

Renting to a friend can complicate things, especially if you're starting below market rent.

Is there anyone in your local market you could take out to lunch who does flips?