Hi Lindsay, I think your lighthouse looks fine stylistically for an illustration. In fact I think it has that illustrated look, with simplified shapes, line and wash, and clean colors. Also, illustrated books and comic books can be very realistic in style. Two examples that immediately jump to mind are how James Gurney illustrated the Dinotopia series, and Alex Ross's comic book runs. Here is an example from Ross.
I think this kind of style might not be practical for a regular comic book production timeline, but there is nothing saying you can't.