Changing classes question

[Conradus]

When changing a class, I can always go back and level up the original some more after the change, correct?

You can freely change between classes at any time other than actually being in a combat or duty by simply equipping the appropriate main weapon/tool (provided you did the class unlock quest at the guild), and you can always level up your current class. If you switch to a combat class/job while not in a sanctuary, you will get a fairly long initial cooldown on your actions, so it'll be a minute before you can actually do anything other than auto-attack. As far as action bars, not only are they saved, but you can choose to make them class specific or shared, as you like--I believe that the default is 1-4 are set for each class while 5-8 are shared, but this can be changed to fit your preference.