Diplomacy Crew Skill

This gives your character the ability to negotiate with others which can really help you pursuade others into giving you more power and respect.

Treasure Hunting Crew Skill

This gives you the ability to recover valuable items by investigating different clues. Working out these clues will award you with many different items which will benefit your character.

Underworld Trading Crew Skill

Will be some sort of smuggling missions for companions.

Investigation Crew Skill

There is a possibility that this crew skill will allow you to discover rare quests.