I doubt they'd be rated, after the stresses of launch, for long-term habitation,
Is anything at all "rated" for long term habitation in space. You'd never get the physical ailments consequent on a 6-month spaceflight past any industrial safety laws. Seriously, not.
but there's going to be ample need for the bulk storage of mass.
You've gone from step 1 to step 100 without showing any of your intermediate working. This blank assertion does not convince me. Would you fill in a few of the steps by which you arrived at that assertion.
perfectly good organics and mass that might be someday useful in orbit, [...] Then the containers themselves could be used as raw material for some hypothetical future process.
Hmm. "GIGO". Not "garbage in, garbage out," but "getting it in and getting it out". Unless you're *only* talking about sewage. But having had to unblock the family shitter more than a few times after the sister blocked it with nappies (EN_US : diapers), I don't relish that task in zero-g. "Who'd use diapers?" I hear you say. Well, having friend who are saturation divers, and never once having heard someone on a spacewalk tell ground control that they need to go inside for a shit
Tanks are good for getting liquids and gasses in and out ; for pastes and solids, not so good.
Also, for long term storage, you're either going to need a gas venting system (in which case you've got a rocket effect which you've got to control
What is that "zeroth law of science"? Oh yes, "It's not as simple as that."