All ISPs are legally obligated to forward that shit to you. The alerts are not from spectrum, they're just relaying the information.
Right now, copyright owners do not have legal permission to find out who you are directly without a court order. They would only seek that information if they were planning to file a lawsuit.
Media companies know, from the Napster incident, that such actions can backfire stupendously. It's rare that they even bother anymore. I can go into detail on why, but I'll leave it out for brevity.
So they send the notice to your ISP, who is legally obligated to match the information on the notice to the subscriber and forward the notice to you.
For many, this goes to an ISP provided mailbox, which most people ignore the existence of it. Clearly spectrum operates differently.
The notices are from copyright holders who have no idea who you are, and can't determine that information unless they intend to sue you. So those can be, for the most part, ignored.
It's not your ISPs fault that you got those. They couldn't give a shit less about what you do on their service, or what you download. They just want you to pay your bill every month and keep the gravy train rolling.
Yes and no.
Modern HTTPS connections send the URL you are connecting to in the initial hello, so the remote webserver knows what security certificate to use when you connect. A lot of web servers host multiple sites, especially for smaller webpages, and so it doesn't assume that since you connected to that specific webserver, that you're connecting to the site that the webserver is hosting, even if it's only hosting a single site.
This can leak the data to anyone sniffing the traffic.
You can also determine some traffic by IP address, this is for larger web services like Facebook, youtube and other sites of similar size. They load balance groups of IPs for their traffic, all are serving the same data. So if you connect to an IP that's owned by Facebook, for example, then your actions can be easily derived.
Since the connection is still secured by TLS, the content can't be deciphered, but the location you are going to absolutely can.
It really depends on a lot of factors.