Wow, these are crazy. It's very difficult to know how to play these at a glance, with so many different things going on. On the other hand they're certainly not ignorable - they offer so much in terms of VP.
At a guess, I can see Opulent Castle being very important. If you have an engine that can draw a good chunk of your Castles/starting Estates, Opulent Castle will start giving +$6 or more, letting you easily buy the last three cards in the pile. There are a couple of ready-made ways to snipe the Opulent from your opponent - you can Haunted Castle them and buy it after their bad turn; or you can Small Castle into it.
If you are contested for Castles, I see Humble and Kings losting their lustre, especially with the two trashing Castles. I think the focus might shift towards building an engine then incorporating Opulent/Sprawling/Grand Castles for lots of money and VPs.