This whole concept of a satire of a stock hero and his childhood friend serving as antagonist is done really well in Rebuild World (Katsuya). I don't have high hopes for this living up to that.
He had the slap coming. I highly recommend reading the books if you want to know more, the manga is adapting them at a glacial pace, compared to the speed of just reading through those.
Sometimes Light Novel versions of works are 1 to 1, and sometimes completely different.
These webnovels are usually free, and you get what you pay for.
Watching this scene in the show I was thinking "they're trying to say the dwarf is gay without being too up front".
Then I come and see this and they joke about An*l sex.