Hello,
I have exactly the same questions, the support matrix seems to either be out of date, or Chargeback 2.7 for SP does not support vCloud 5.5.2.2 or vCenter 5.5 U2.....
We are getting incorrect billing reports from chargeback, for example a 4GB vAPP is created in vCloud, it picks that up, however if the customer allocates more memory to the vAPP, say another 4GB, chargeback will still only report the vApp having 4GB.... This is a major issue as revenue is being lost....