Thank you for all your work with this site and answering hard questions that sometimes members of the Church are unprepared and unequipped to answer.
I graduated from High School in 2010 and have experienced first hand the Fellowship of Christian Athletes. I was never personally a member, but once I did happen to be in the vicinity of a FCA meeting. It is likely that each school does things differently, however at my school FCA was a weekly worship service that implemented instrumental music. Both males and females were a part of the leadership in the singing. Many of the people in this assembly were not all athletes, most of them were the more religious denominational students at school. FCA is not necessarily allowed to intrude into sports; they can provide activities for students to participate in, but it is not restricted to athletes. As you said, it offers little other than an avenue for all denominations to get together and promotes individual faith. Even from the standpoint of having an opportunity to reach or teach others, there really are not any opportunities to do so. Most of the speaking was done by the song leader between songs and performances -- not sure of the distinction honestly. Generally other students that are members of the Church tend to avoid this group, even the more 'progressive' ones. Hopefully this can help in your efforts!
Thank you for sharing your observations. I'm sure it will help others.