Hi Matt- long time.
On the XCP usage and role question:
I own most of the original XCPs and in the past I have been trying to get a clear answer for this same exact question. Way before the ethereum system adaptation, the answers were quite different... is this the only remaining real usage for XCP? wasnt it supposed to be used in every CP related transaction in the same manner you just described with ETH type contracts? what about a future financial transaction in a CP powered (symbiont for example) system? is the vision now that it wont require XCP? what was the answer for this before the ETH adapation?