Not that you asked, but I normally strenuously resist the idea of CMOD servers without TSM -- in my experience, the overwhelming majority of data in CMOD is 'data at rest' and is rarely (if ever) accessed. This makes it the perfect candidate for tape. I try to urge folks to do more research and find their most used data, and cache that -- rather than trying to cram everything onto hot, power-hungry, spinning disks.
That having been said...
You're right, that the way to get data out of TSM is "arsadmin retrieve" and the way to get things into cache is 'arsadmin store'. I think the "implication" you're looking at is for loading a NEW object into cache AND TSM at the same time.
The way to determine if a file exists in the cache is to check the retr directory. The TSM filespace ID = Application Group ID Name. Check here: /arscache/cache/retr/<AGID>/<TYPE>/<OBJ>
Where AGID is the Application Group ID Name (also in arsag under the column agid_name).
and TYPE is DOC (document) or RES (resource data).
and OBJ is the CMOD object name - a number, followed by FAA, followed by a series of letters, and optionally a $ or a 1.
It's a big job -- good luck!
-JD.