Funny, I've actually been LOOKING for a Mahalo U30 tenor (outside of Australia). I don't know I'd actually buy it once I found it, but I want to play one. Rounded back, geared tuners, affordable to say the least. From what I have read elsewhere, the U30 is a decent Mahalo! Supposedly the soprano and concert models in want of a set-up, adjusting the action at the saddle, changing the strings etc, so you're on the right track there (you meant sand down the SADDLE, right?).
But I think the prospects are pretty favorable that when all is said and done, you could have a good uke on your hands. As far as learning to play, this is the right place for that. Check out the lessons, and the uke-minutes, look for the tabs section in the forum and you'll be good-to-G-O.