Is mathematical aptitude the limit of how well I can do in an interdisciplinary life science field as a computer scientist?
Speaking as a computer scientist who works with life sciences: there is a lot more use for computer science than just modeling.

Consider:


Who makes and maintains the instruments?
Who handles LIMS development and deployment?
Who develops automation systems and precision protocols?
Who develops the control mechanisms that actually implement biomedical intervention concepts?
Who develops taxonomies, interchange standards, and data representations?


This just scratches the surface of computer science opportunities in the biomedical 
Unfortunately, the view that you hold of "you're either an experimentalist or a modeler" is far too prevalent in biomedical culture, and computer scientists often get little respect for their contributions.  That culture is starting to shift however, and especially in younger and more engineering-centric subfields like synthetic biology... and especially in some of the awesome things the younger practitioners are doing.