Fail2ban does all of nothing to protect you. At best it keeps the noise in the logs down a bit.

Competent attackers tend to use a botnet, blocking and rate limiting does jack shit against 10,000 IPs.

It's fine, but it's a good idea to disable password authentication and only permit public key auth. Using a non-standard port helps reduce the spam in the logs a bit.

It's pretty sensible behavior. Things that are desirable on desktop-like multicore systems aren't always desirable on manycore systems.

The ability to thrash on 128 cores is probably not something anyone is missing.

Anywhere between 250W-1000W depending on load. Daily average is about 400W right now.