leski: J-club and NSA are two separate organisation. J-club is aimed at breaking language barriers between Japanese people and Japanese students. NSA is aimed at Japanese people forming a community on campus.
I had so much trouble with kanji too. The trick is to write out the kanji, then cover the characters and focus on the hiragana, then write out the kanji. It's a matter of remembering the association between the hiragana and the kanji, not just the 'picture' made by the kanji - it's pretty useless if you dont know what it says or means.
Cheezels: I would recommend doing
Professional Japanese, which will introduce you to Japanese language in the workplace. It is really quite different to 'normal' Japanese and will make you more employable as a Japanese speaker. There used to be a course called Hospitality Japanese - I was going to recommend it but it's disappeared :/ I did a bit of Business Japanese, I havent done the other courses, but from what I've heard, the courses are intense but good.
3A and 3B use the same textbook, but a new reader will be required for 3B. You'll also have a project in 3B, and depending on what you do you might have to buy books for that as well.