Go for it! Many GGs are OK with the CDing as long as it doesn't impact their romantic/sexual lives. Look at all the helpful and supportive sales persons! They likely wouldn't be as supportive of their own CD husbands if the husbands required them to be in a romantic/sexual relationship.
I applaud the two of you for being honest about your sexual needs, and especially for you respecting hers! Given that a sexual/romantic relationship is not in your futures and you are both pragmatic about it, why not be friends. Maybe you'll find someone you are more sexually compatible with too!
It has nothing to do with fear and negative self-perception and everything to do with sexual preferences. How much introspection is required for a hetero GG to determine she is not attracted to femininity. Likewise, most CDers would not be attracted to butch females!