Can panettone paper molds be used for other things?
Yes, they can be used for other dishes. I've never done it myself, so I cannot elaborate.

I scanned the Amazon reviews for a panettone paper. I saw people had used them for sweet bread, muffins, some used it for cheesecake. I imagine the papers could be used for souffles and quiches.

One Amazon reviewer mentioned you may need to increase the moisture in your recipe since the paper soaks up some of the liquid.

In any use, I would pan it in a way where spillage would be contained.