How did the bad guy recognize and correctly name the TARDIS and not know who the Doctor is?
One question about the bad guy — why didn’t he just send Rosa Parks back in time? He couldn’t harm her, but he could send people back in time. Seems a much easier way to accomplish his aims.
It would have been kinda funny if they didn't realize what was up, and the Doctor would just give up her spot for Rosa Parks, only to realize she just has screwed up the timeline and has to fix things.One thing I found quite compelling was the unpleasant realisation that the Doctor and Graham needed to *be* the white people taking up the space so the driver had to tell Parks to move. You could see they so wanted to help, but knew they couldn't.
It was important that they didn't make to that the Doctor inspired Parks, or caused the events, or anything like that. It was a strong choice to have nobody even really notice the Doctor, and for none of the primary characters agency to be altered or reduced. They all made the choices and did the things they did on their own initiative, and the Doctor had nothing to do that. Instead, she was busy dealing with a time traveller and ensuring he didn't stop it, while staying out of the way.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.