Some questions from a rookie!

[Nikorayu]

1: You can unlock and lvl every craft/gathering class.

3: Free Companies are basically the same as guilds.

2 and 4: Yes, jobs such as Bard and Monk are each unlocked by having the main class for them at 30 and sub-class at 15. A job such as White Mage require lvl 30 Conjurer and lvl 15 Arcanist. More about which classes the jobs require can be found here http://finalfantasy.wikia.com/wiki/F...ntasy_XIV#Jobs

I hope that's the info you seek for the following questions. I left out your fifth question because I don't know the answer to it.