I'm confused about several aspects of editing, specifically editing questions.

I often see editors such as the speedy Jamal and others making relatively minor edits (such as changing "i" to "I"). However the help center seems to advise against such edits and even the system will block them.

Several of my minor edits were rejected which made me wonder: is making edits of this kind something that's only allowed to be done by high-rep users?

The other issue is people seemingly ignoring edits and then making the same edit themselves. As I can not yet review edits I was wondering if there is no indication that an edit is pending when someone tries to edit a question? I don't see a reason for why people would discard an edit only to make the same edit themselves.