You can play harmonics on the frets where the dots are located, but I wouldn't use harmonics, except for the octaves, to tune the guitar. It's too complicated to explain here, but an article on equal tempered tuning, that I found on Mark Hanson's Web site,
www.blueclickeything.com
might help.

Shubb makes a capo for flat, classical style fingerboards too. To capo only five strings, you just put the capo on a little off center.

EZR