Most of the technical points listed here are pretty much entirely mitigated by TLS. Exit nodes can of course deny access to specific sites, but hidden services suffer from comparable (or worse) issues.
There are no other practical attacks that malicious exit nodes could execute against sites using TLS and HSTS preload lists. If you’re a website administrator, fixing those things should be your priority before implementing onion addresses.
Onion addresses also come with slight drawbacks. They’re difficult for users and more vulnerable to phishing. Hidden services are also extremely vulnerable to CPU-based DoS attacks.
There are no other practical attacks that malicious exit nodes could execute against sites using TLS and HSTS preload lists. If you’re a website administrator, fixing those things should be your priority before implementing onion addresses.
Onion addresses also come with slight drawbacks. They’re difficult for users and more vulnerable to phishing. Hidden services are also extremely vulnerable to CPU-based DoS attacks.