No. Addresses are not broadcast. Transactions are broadcast.
For that matter, addresses don't even exist at the transaction or blockchain level of the technology. Addresses are something that we humans use to make it easier to talk about the exchange of control over value. The wallets convert those "addresses" into scripts (in other words "small computer programs") that encumber the value with some requirement that must be met before that value can be used to fund another transaction. Typically this requirement is a signature from a specific private key.
Every full node peer on the network. That's why it takes so long and uses so much disk space for full nodes (such as Bitcoin Core) to "synchronize" with the network. They are downloading the entire blockchain and hosting it for all their connected peers.
Yes. Multiple physical appearances. One copy on each and every full node peer on the network.
Anybody that wants to run a full node peer.
Thanks Danny, I am currently trying to learn more about the backend of Bitcoin. I sort of knew a little bit about it but I guess I never thought what actually is broadcasted from transaction to transaction. Again, thanks for the answers I might have some more questions in a bit doing some more research.