CU and Church
Just looking at CU should show us how it is not a church. It is not self sufficient in gifts (e.g. Teaching, leadership etc), it is an extremely narrow age-range of believers, it doesn't attempt to identify itself as a church, by practicing baptism or the Lords supper...
Having said that, CU can often look quite like a church! That's because, the moment we say 'we're just about evangelism', you've also just said 'we'll train people for evangelism, put people into fellowship with like-minded people to encourage each other in evangelism, pray for our evangelism, provide teaching to help people to be witnesses where they are' etc.
But you have to remember that you are not a church, and let the aims limit you!! In everything that the CU does, the goal aim should be being directly fulfilled, or else supported. There are lots of areas that the CU shouldn't be involved in, including pastoral care, social action, prayer for wider issues around the world etc. When these issues arise, you should point people to their local church.
This is why it is really key for people to be involved in a local church. CU is the missionary arm of the local church, so it is definitely NOT a replacement for church. People in CU need to be plugged into a local church as the lifelong primary place for Christian community, teaching, discipleship and pastoral care.
Keep asking about CU: what are your unique opportunities (compared to the churches)? How can you exploit those?
(to be cont...)