RE: Some might not require you to salute them, having the "work for a living" type attitude.
it's usually non-commissioned officers and petty officers that have this attitude. Warrant officers are more likely to have the "hey, the second word in warrant officer is the word OFFICER! why am I being treated differently.." attitude. A warrant officer is considered a specialist in his field, while a commissioned officer is expected to be a generalist. Both are more about what they know, (management) not what they do (product or service).
When in doubt, whip it out.
Same motto I adhere to in my dating life ...
for the record, a CWO has a warrant, not a commission, that's why they are warrant officers. Some of the senior ranks of warrant officers actually DO have commissions, so you're basically correct.