[Ethereum] Removing a peer/node

No, there is no peer discovery methods other than modifying the boot nodes.

The IP addresses are configured in the source code of the clients. If the IP changes, the list of the last bootstrap node that it connected to will change (the old IP will be removed and when the node connects again the new IP will be stored in the list).

What are the peer discovery mechanisms involved in Ethereum? explains a lot.

It's a language thing about the relationship. It's like "people" and "friends". It's not that friends aren't also people. We might say that people are friends because they have a certain relationship to us.

Ethereum nodes are initially alone, and then they seek out other nodes to talk to. When nodes agree to talk, they become peers to each other.

"Peers" is another word for a person just like me with similar knowledge and abilities. A node's peers are other nodes that work the same way. Nodes talk to the network through their peers, and learn about the network from their peers.

Hope it helps.