We just recently changed to stage 3 and so far so good.
Does your baby 'mash' or making 'chewing' motions yet? Does he have any teeth? These are two signs that he may be ready for stage 3.
We also put a few of the Gerber puffs on the high chair tray after lunch and dinner so he can practice his pincer grasp and learn to feed himself.
I say give it a try - if he doesn't like it, then you can always go back to stage 2 and wait it out.
I agree with the advice about juice. Personally, I'm not going to be using juice as it is mostly sugar, but I know many mothers who have used juice and have had absolutely no issues with it. If you do use juice, use it exclusively in a sippy cup and not the bottle.
If you want tips on how to get your baby to sleep through the night, you can try reading "Healthy Sleep Habits, Happy Child" by Dr. Marc Weissbluth. I realize it doesn't float everyone's boat, but if you're truly interested in helping your child sleep through the night it might be worth a read. If you hate it or disagree with it, you never have to use the tips!