1) Your classes can take 10 abilities from other classes, but not traits. Once you get to 30, you can start a job; each job can take 5 abilities from two other classes. Which classes you can take from depends on your job. Any class below your highest-levelled class will receive an exp bonus when levelling.

2) Unacceptable. One more stunt like this and you're out of the FC.

3) Ok.