Yes, the second team is then considered "on the clock". If the Rams had wanted to, they could have signed a player after the Dolphins signed Long.
Nope. Incorrect. They can talk to players, but can't sign them. As Tommy said they may change that, but probably won't. They asked the Commissioner about this on NFL Network, and he basically said exactly what Guru just said- if you allow the second team to do it, you then will have the third team wanting to do it. If you allow them, you then have the fourth team wanting to do it, and so on and so forth. It then takes away from the draft itself.