Terra. There's all the Terra is Xehanort theories so I wish to know about him. Also I think it will be enjoyable to play as him. He seems to have a style similar to my gameplaying I think.
I like: Sacred Moon it has a nice melody and fits The World That Never Was. Passion (Orchestraited) it had a nice tune and beat and I thought it went good with the story of Kingdom Hearts.
I usually choose the sword since I'm a offensive person. Though it's boost can be given with other boost so the staff might help more. I usally choose ether the sword or staff. It depends on your gamplay style and what type of person you are.
I like it better. I mean, getting used to it was worth it for me. If it can save space and help you attack, then it's worth it. I thought it was something else that made Kingdom Hearts II unique.