Now I'm going to reimagine the game of Pac-Man as a wedge of cheese flailing about and knocking over rows of wineglasses.
Dragons can mate with everything. It's one of their powers. As the show already fills the Everfree with the monter manual, I see no reason to not have half-dragons.

Discord is the result of a dragon literally mating with everything.
Do you think ponies whose mane and tail colors are different from each other are considered fashionable or unfashionable?
The original Rainbow Dash was considered very fashionable, wasn't she? It might be different for rainbow ponies though, as even the toys of the new Rainbow Dash have the colors segregated.
Scootaloo doesn't get much attention because most of her activities would get the show kicked off the air. They're of a rather clandestine, stalkerish sort.
Really? More so than Sweetie Belle and Apple Bloom, who I can actually recall snooping around and messing with other people's stuff without permission?