I also think she loves the idea of the title. If she didn't care about it, we wouldn't have had all those articles written about her by her friends with blogs, and she certainly wouldn't have contacted the Indian press to publicize their honeymoon. If a title wasn't a big deal, she wouldn't have signed "of Austria" and used the Archducal title on the birth announcement.
I am curious about how often her parents come to visit her in Europe. They've still got kids at home, but the older kids are definitely old enough to watch the younger kids if the parents wanted to visit; or, her mother could visit since the younger kids aren't babies needing a mother around 24/7 to breastfeed them. The youngest is probably around 10 by now. I think they're probably just middle class people with a lot of kids, so their budget may not allow for European travel.
Marie-Christine and her husband were at the wedding. I recall seeing pictures of them at the church. IIRC, when their Knot wedding site was visible to the public, it stated that MC's son Leopold was going to be in the wedding. Leopold didn't travel with them to the US, and certainly wasn't in the wedding, so I'm not sure what happened that kept him home (and I think they were living in Argentina at the time, so it wasn't like Leo was unable to fly). I've never seen a picture or video with MC and Katie interacting with each other, so it wouldn't surprise me if MC didn't like Katie. She seems like she's kind of snobby like her father, but that's just my opinion based on pictures I've seen.