Yes, whenever I'm not using it.

From boot menu to booted is only about 6 seconds (gradually tweaking that to be faster).

>gradually tweaking that to be faster

Do elaborate please!

    systemd-analyze blame

Gives me a list of stuff and how long it takes them to start. For this machine I don't need most of them, so it's a case of then

    systemctl mask SERVICENAME

Or systemctl disable SERVICENAME

Never. I have a Macbook air and I only close it without powering it off.

I reboot from windows to linux, but essentially never turn it off unless I have very good reason--traveling, for instance.

I just turn my notebook into sleep.

Every night or while traveling

Maybe around once a month, on a MacBook Air.

Nope

Yes. I only use a laptop when work requires me to travel. The vast majority of its life it spends turned off and locked up in my desk.

Never