If you don't then there are ry only two things you need to know how to do:
If you didn't push to origin do an ammend. If you did, revert soft and commit the previous code to revert it (you can also put a stash or patch to apply it back).
Which frankly is what the article does, basically.
You need to expand on this because i don't quite understand what you mean, are you talking about "fix typo" commits or are we getting to the level of just committing away until things work and then not cleaning up the work later on? The linked article doesn't cover rebasing or squashing commits, which can be pretty powerful when used correctly.
Your commit log is the one thing that is immutably linked to your code changes. Your documentation isn't, the comments in your code aren't, you will forget why you made a change, anyone reviewing your logs needs to understand your intention, your bug tracker will probably change several times over the life of a project, and so on. So, make an effort to have a commit log that is clean and comprehensive and commits that don't break tests.
I go into this in more detail in a talk i gave last week: https://www.youtube.com/watch?v=9OHAq8dCoS4
You get your cake and you can eat it too.
Be verbose in your commit messages and don't worry about merge commits, it will pay dividends later.
Yes, that sounds as easy as anything that accepts the idea of "let's do this the shitty-but-quick way now, and pay the technical debt later". So yes, it is "easier" to work with in the beginning.
On the other hand, if I had to inherit your repository that was developed by "not caring about history", I would probably have to hunt you down and kill you. So there's that.
Yep. Some people just want to keep taking technical debt on (read: hack-it-'till-it-works), which makes them likely candidates for a good thrashing in some dark blind street in the middle of the night. And some don't even get it after that. Actually, now that you made me think about it, most people in this industry aren't really computer people material, that's the problem.