I'm in your shoes!!
I know what you're dealing with! I've been in a "Harry and Sally" situation with a libra for over two years. And I, like you, am a Capricorn. He and I both have our moons in Aquarius. From what I've read, Caps and Libras - both being cardinal signs - want to lead. And if this can be "overcome" meaning balanced to the Libra and "secure" to the Cap then its a very fruitful relationship. Cap needs to feel safe yet there's a freedom quality in Libra that helps temper her extremes. Libra likes the freeflow and floats like a butterfly but Cap can bring some productiveness and practicality in his life. This is all IF they collectively agree to seek that balance. IMHO, if this centerpoint can be acheived then it can be a very rewarding relationship.
Remember, air vs. earth. The air can contain the earth, as in a cave. We think it as being safe and secure, but the air wants to flow, Libra not really realizing that a little structure can do him good. We (Caps) become equally distraught if that air moves too much and stirs us up, but we can fail to notice that some beautiful and fruitful changes can occur. If the wind is always blowing erosion (weariness to Cap) will happen but trapped air can stagnate and not nourish anything! I think its all about Temperance (which always appears in our readings!), sort of mixing oil with water, blending opposites. Motion is needed to avoid that fine-line of separation. A positive? Always moving and growing!!
I'm still in the "are we friends or more" stage he keeps me guessing, that indecisive Libran. (2 of Wands also shows up!) but hope I have a chance to work for that balance someday... then I'll be on your shoes, LOL!
~ january
PS: same goes with $$, caps horde and build a nest, libras spend it with the wind... material vs. concept.