Better to Establish or Attack Early?

It is always best to develop with threats. Be on a constant lookout to attack. Poke around the opponent's defenses to find a way in. When the opportunity to attack presents itself, take a moment to consider whether the attack is worth pursuing. Should you attack immediately, or should you prepare for a bit? This is the general idea. In practice, it is not that easy to implement because normally the opponent will not let you.

Good luck.

Sure. It would be silly if you could launch sound and dangerous attacks every time if your opponent has not done anything wrong. If your opponent is greeding for material instead of developing while you've developed then you got good grounds for attacking. If both you and your opponent spent your moves developing pieces then naturally you're most likely not going to be able to attack. I don't see anything odd with this.

I agree with most previous posters. Do not 'attack early' if this means positional disadvantages, e.g. going late in development or weakening squares, unless you are sure to get something in exchange. You cannot decide to attack just because you want it, you need some foundation in the opponent's incorrect play.