which games should I watch?

I heard learning from lower rated masters can "teach" you bad habits, which you can not un-learn later, so easily. that's why they stay as CM,NM,FM or IM they say. So what about watching? watching their games do harm me?

But GMs usually play Bullet.. it's too fast to understand.

what do we do?

Why would a grandmaster be afraid of cheating?

any answer to the main question?

If I were to make a choice between GM's playing bullet, or lower rated IM's and Masters playing rapid, I would watch the games with the Rapid time control.

But if I was looking for alternative options, I would browse through Youtube and for old streams of major events. The other option that I'm more likely to use is to study games on a chess database.

Unless you're analyzing with an engine and pausing often, you won’t learn much from it. You’ll just admire speed or tactics.

Bobby Fischer games! or brilliant chess moves in a recent games of yours