He totally will follow through and have her cater something. He loves hosting (although he'll likely not go for fancy ball next time with this crowd). He is willing to answer questions about magic, but not being very magical himself, might direct her to Alucard for more details. In general, the magic in the palace is fairly old, enchantments built into the materials of it as it was built, and also wrought into all the decor/plates/silverware when they were made. And by "fairly old" I mean probably at least a couple hundred years? They're regularly checked and refreshed as needed, but it's the best kind of magic work that money can buy (literally), so it holds up well. Arnesian magic is very elemental, so it's all about working with stone and metal and glass and so on.
Mal is super ridiculously happy with his married life. Even though it's really not very exciting. They recently acquired a goat. XD