Yeah, unless you already know a bit about the hitboxes it's hard to tell what moves they belong to. That said however, they generally follow the same pattern:
- Glide attack
- Neutral combo
- Dash attack
- F-tilt (up, side, down)
- U-tilt
- D-tilt
- F-smash (up, side, down)
- U-smash
- D-smash
- Nair
- Fair
- Bair
- Uair
- Dair
- Nair/fair/bair/uair/dair landing
- Grab (standing, running, pivot)
- Pummel
- B-throw, F-throw, U-throw, D-throw (for the hitboxes of multihit throws)
- Floor attacks (back, front)
- Edge attacks (fast, slow)
- Floor attack (trip)
- Unique item hitboxes (e.g. Marth f-smash)
- Taunt
- Specials (usually neutral, side, up, down, FS)
Something that I find helps with this is looking at the ID numbers - a Hitbox 0 usually shows a new group of hitboxes, for example, and seeing four hitboxes with IDs of 0-1-2-3 is almost a guarentee they're all part of the same segment. Some of the attributes are also a big help (a 18%-damage hitbox with an angle of 90 is probably an u-smash, for example).
Hurtboxes are not yet implemented.
In the picker dialog it says what bone (number) the hitbox is attached to.