Convertible: Yes > You are able to turn this piece to materia after it has reached 100% spiritbond (you will need to be in certain point of your main scenario quest to unlock this feature). You can then sell the materia or meld it on a piece of gear for additional stat boost (you won't need to worry about materia melding until level 60, though).

Projectable: Yes > You are able to glamour the piece to look like another piece (you have to be level 50 to unlock this feature).

Desynthesizable: Yes > After having leveled your crafters (level 30 to unlock this feature), you will be able to desynthesise this piece to gain crafting materials.

Crest-Worthy: No > You are not able to place a Free Company crest on this piece.

To get to Limsa, it's best to progress in your main scenario far enough to unlock airship travel (around level 15 quest I think). When travelling to Limsa for the first time, don't forget to attune to the Aetheryte there to be able to teleport back whenever.