In light of this, I consider some of the quoted examples to be highly suspect.
E.g. "Stop making everything a race issue" which could possibly be said because the person who said it does actually consider that the other person is doing just that, and is offended by it.
or:
"I don't want to hear about your holiday to South Africa. It's nowhere near where I'm from" which might be said by someone who is sick of hearing about someone endlessly going on about their holiday, and from 'where they are from' might be referring to their poor background and that there is no way they could afford such a holiday.
But I think all that is intended is for people to better understand how their comments might be construed - I someone want to be offensive, then they will be, but this is to help others who don't want to be offensive to avoid inadvertently causing offence.
So on your first example that could cut both ways - firstly toward individuals making low level racist comments without realising or meaning to, but also in reverse towards individuals that inadvertently consider things to have a racist element when they don't.
On the holiday one - all it might mean is someone simply says 'I'm sick of hearing about your holiday yet again, I'm bored of it and you need to realise that I've never had the opportunity to go on a holiday like that'
I agree that I'm not sure these are the best examples - the 'where are you really from' - when that person may have been born and grown up in East London (as an example) is a better one, and again easily avoided. Likewise being compared with someone, anyone merely because you are both black, or both asian is pretty offensive and easily avoided.