I have studied the London opening system on lichess.org. What really clicked with me are the systems two main ideas: (1) develop a defensive structure which (2) allows you to crash black's kingside castle by pushing pawns with rooks behind them (and very often crush your opponent).

What you have is plan A, which is to crash black's king side, and if black doesn't castle you return to plan B, which is to improvise from a very strong defensive posture. The main point is that you have plan A with a very specific way to win in mind.

I am /not/ asking about opening principles. I am asking about the specific ideas of the Ruy Lopez. I understand how it gets your pieces out fast, is aggressive, and allows for a fast castle. But what approach or strategy does the Ruy Lopez aim for? 

In my own games, the best idea I have is to position my rook in the center file (because I can castle quickly) and try to open up the center and use a discovered attack on the king or queen by exposing my rook. But is this 'classical'?