Once I take my dog for a walk, play with him, do some cleaning, and sit down to eat dinner, I'm usually brain dead for the day!

Hard Money Lending (HML) for this purpose.Conventional LendingWill Require a Down Payment in all scenariosWon't allow a rehab budget on a duplexDoes have a 30 year fixed rate optionMight not approve the property at all if it's in very rough condition or if 1 major thing is wrong (like a foundation or a roof)Can be cumbersome, 30 days to closeLow interest rateHard Money LendingWon't Require a Down PaymentWill allow rehabShort term money only (so you have to refinance if you are keeping the property)Doesn't care about condition since you will have the rehab included in the loanSuper easy, can close quicklyHigher rate and higher feesSo here's how this all plays out:Conventional lending - will require 25% down payment on a duplex investment property ($34,250 based on your numbers above) + closing costs ($7,000?) 

These people play by different rules,  don't think you'll be an exception, you won't.. you'll just learn why people like me are so salty! 

So its a long term play for us.

I’m considering two separate options for the rental, depending on cost/pay off:-Simply reconfigure the layout and make it more functional and appealing to renters.Or-Add square footage (possibly a bed/bath) and hopefully increase the value, functionality, and what it could bring in for rent.But seeing as how this is my first investment property my gut is telling me to play it a little more conservative and let these ideas simmer before pulling the trigger.

if the wall above is brick it could have a dead load between 40 and 160 psf.

It'd be like suing a "dead person." 

I spent a few years playing hockey near there.

The cashflow play on Oahu is extremely challenging.

I am using real estate for long term retirement play.