Hello
You said "KoAloha plays really nicely but is 20 cents sharp almost right off the bat at the first fret". This sounds like the nut slots are cut too high. A quick way to test is to tune each string at the first fret (easy if you have a chromatic tuner), and then see if the note on the second fret is right on or sharp. If the nut slot is too high, the second-fret note should be right on if you tune the first-fret note.
And you *can* lower the nut slots yourself, but if you too far, you get buzz on open strings. Besides, an expert luthier can spot other problems (such as lifting frets, warped neck, bowed neck, saddle too high etc) so a visit to a good luthier is worth your time and money.
Cheers
Chief