Definitely. Crown molding is not usually used in modern and contemporary designs, but it looks entirely appropriate in houses either from a certain era or inspired by an earlier era.

My home and furnishings are traditional - but probably not considered a specific style (french, english, mediterranean, etc.). The decor is comfortable. I like the look of board and batten, as well as picture frame molding and tongue and grove wainscoting. Should these be uniform? Can they be combined (by room) without confusing styles?

There are lots of different styles. I'm sure you could find something to suit your property.