[nickik]

Wrong. The exit-node might control the traffic but that does not know where you came from. You need to watch the connection into the torrnetwork as well.

When you connect to https its pretty hard and risky for the exit node. If the user uses https with pinning its even harder and more risky.

The Tor Network is not perfect, nothing is in this space. So you need to make a more detailed analysis then yours to evaluate it.