Hi el hwz,
Whether to skip and move to JLPT 3 direct would depend on your objective of learnin this language.
Is is for job opportunity? Or interest?
I am a more down to earth person and belived that the foundation of learning language is the most important.
Along the way, when you study from elementary, you will gradually pick up new vocab, grammar which i think is more fun compared to pressuring yourselves to memorise them in a short period of time.
But if you are a student or have a lot of time then can consider to skip 4 bah.
Anyway having JLPT 4,3,2,1 is just a basic guide.
As for School , JCS is still the best. I am with JCS now. Although the class size is very big =)
Last time, I was with Inoue. Not bad actually with more personal and family touch.
The teacher will chit chat with you in japanese thus drilling your conversational skill.
I had a great time there , the place that inspired me to continue to study the language =)