Milb.com is notorious for making a switch to a players profile. Since he was a RHH when drafted, even if he starts hitting solely LH, it probably wouldn't be changed for 2-3 years. Juan Francisco was in AA and still listed as a switch hitter and 180 pounds before it was changed. He never did either of those things in the US. They just never made the change.
And as for Hamilton, he is considered an above average to plus shortstop. Its more about whether his bat develops because defensively, the kid has some serious tools.