I'm aware of what constitutes a decent password, but typing in 15-30 random characters each time I lock my computer screen is starting to get a bit taxing.

How secure does my user password really need to be and what are the threats to it? Does the same apply to a root-enabled user as a "regular" user when it comes to password security?

For context, my threat model doesn't need to account for real people breaking in and accessing my computer, the damage would be very contained.

Bonus question - what are the risks of having a weak password on a root user on a spare laptop on the same network as my main device that is used exclusively for web browsing? Thanks.