Two points:
We are adding support for all the file property functions. In coming Mathematica versions and CloudObject paclet updates, FileDate and FileByteCount on a CloudObject should work as expected.
CloudObjectInformation is being improved to be more performant. In particular, you can ask for a single property:
CloudObjectInformation[obj, "Path"]
or a subset of properties:
CloudObjectInformation[obj, {"FileByteCount", "LastAccessed"}]
And only the information requested will be returned from the cloud, making it a faster call.
Further, CloudObjectInformation[obj, "UUID"] is optimized to return immediately with no network call if obj is a CloudObject expression with a URL in the canonical by-UUID format that CloudObject[] returns.
Also, you can query multiple objects at the same time, e.g.
CloudObjectInformation[CloudObjects["Type" -> Delayed], {"UUID", "Path"}]
and this returns its information in one efficient network call.