It means "and all the advantages that come from being the host." I assume he is referring to being at home and not having to travel, having lots of people in the stands and in the media who support them, and the data which shows that home teams win more often than you would expect, in nearly all sports.

I'm not sure, it isn't something that would be said in British English. We might say "After all" which would mean "Considering they are the host country" If anything, I think this is the meaning Could be short for "and all that" which would mean the same as above.