It seems where you've chosen to move doesn't line up with your goal of reaching financial freedom?

@Sunny Wu of course the tenants don't want to pay!

You would need to let them know you are 2nd lender and want to pay the loan off.

The credit score is the single best indicator of how one pays their financial obligations.

Get a paying job with the 40 hours you free up.

I’m over here on Big Island, up in the Kohala coast, and it offers some resort areas too on the sunny western side similar to Ko Olina on Oahu.So things to consider are:- Which Island- Your budget- Will you be financing or paying cash?  

Now, you need to figure out how to find deals and pay for them.

Quote from @Jerome Morelos: I used a fixed rate second to finance the ADU, paying about $475/month for it.

Sometimes paying a premium on a home also guarantees a higher demand in the neighborhood and with that may come a higher demand for a rental as well.  

Quote from @Alan Mills: Got an inspection objection back with something I’ve not seen on my other rehab’s (this is a Colorado property):“The seller agrees to have a licensed plumber install external sewer cleanouts per city code and scope the sewer line ensuring its integrity.”This was a full interior/gut rehab and almost everything is brand new.